危害演讲稿(5篇)

第1篇 手机危害英语演讲稿

手机危害英语演讲稿（一）

手机有毒，低头有害，远离手机，抬头做人。

陈彦融

good evening ladies and gentlemen! i am chen yanrong.

today,i would like to take this opportunity to share my perspective about the influence of science and technology. science and technology sounds abstract but it can be seen almost everywhere in different concrete forms,such as the lamps above your head, and the cellphones in your hand .above all,the most closely associated form with our life is the internet ,of course.

as for me ,i have deeply felt the charm of the internet . my best friend went aboard for further study two years ago . at the begining,i didn't get used to that and therefore suffered from melancholy,tossing and turning late at night,missing her terribly.fortunately, my spirits didn't sink for too long as it suddenly occured to me that why don't we keep in touch through the internet? by sharing wechat moments and using video calls ,we didn't drift apart, but became closer instead. even though we are tens of thousands of miles apart, i feel like she's always by my side.

science and technology not only establishes a bridge of communications between friends ,but also offers a broad platform where we can freely e_press ourselves and maybe resonate with people we've never met before.whenever you find your life unsatisfying,on the internet,there 's a free world for you to place your lonely soul. what's more ,we get information through science and technology beyond limitations of time and space.that's why people can unite as one to offer timely help whenever disasters strike.

as it walks into tens of thousands of households,sience and technology has effectively shortened the distance between people .but i believe some of you are not in favor of this viewpoint ,right?maybe you think science and technology is the chief culprit that makes the distance between people's hearts farther and farther,since more and more people are getting network addition,paying too much attention to the virtual world rather than people and things around them. from my point of view ,however,science and technology is not to blame,because what kind of influence it brings into our life depends on how we make use of it. it's as plain as the nose on your face that science and technology does offer us better conditions to bring us together , but we should also keep in mind that only by reflecting on how to use it properly can we fully enjoy the charm of science and technology.

science and technology surrounds and sustains us in the world, making the earth more like a small village where we breathe together ,laugh together and watch the starry sky overhead shoulder to shoulder.

手机危害英语演讲稿（二）

手机有毒，低头有害，远离手机，抬头做人。

陈彦融

good morning, ladies and gentlemen. i’m contestant no._, zhai weiwei.i feel really honor to stand here and make a speech.today i’m going to look together with you in to this question: does modern technology make the interpersonal communication better?

have you ever found that there’s one word we use more frequently nowadays? the answer is-awkward. if you do not believe, please imagine this scene. sunlight floods the earth. the spring breeze is warm and gentle. you’re finally going to meet the one that you usually talk with on the internet. but when it really comes to face to face conversation, you will find it really hard to raise a topic and keep it going. how you wish you two can use wechat even he or she is just in front of you! it just like someone in your mind keeps shouting that it is so awkward!

you are addicted to the virtual world and escaping from the reality. some people call this phenomenon as embarrassing cancer. it is funny, but it is really happening around us. such an issue would like the virus spread to every aspect of interpersonal communication. we began to avoid family party, put on headphones to avoid caring, send massages to someone behind the screen, ignoring the people around you. abandoning yourself to the so-called personal space. gradually, walls between people will be built one after another. walls that we, and even our children, cannot go beyond.

i believe mu_in once said,' days were slower in the past. carriage, horse, and mail did not reach fast. you need your lifetime to just love the person who is right.' but now, the world has changed. when you want to strike up a conversation with a girl, you don't need to hide in somewhere, wondering what to say will make her happy. you just need to pick up your phone and search for nearby people without hesitation. flood of emotion swept over us, leaving only emptiness after ebbing. emotions lack the process of precipitation, becoming impetuous and cheap. if things go on like this, people will ignore the value of emotion, being a slave of modern technology.

of course, i do not want people to return to the primitive society. in my opinion, we need modern technology, and there is no doubt that modern technology will play an important role in our communication. in fact, we should make use of it rather than relying on it. therefore, what we should do is not stubbornly stick to a small circle, but look at the world, look to the future.

ok, that's all of my speech, thanks for your listening.

第2篇 手机的危害演讲稿

手机的危害演讲稿

演讲稿是一种实用性比较强的文稿，是为演讲准备的书面材料。在不断进步的社会中，演讲稿的使用频率越来越高，在写之前，可以先参考范文，以下是小编精心整理的手机的危害演讲稿，欢迎大家分享。

手机的危害演讲稿

手机是我们随时不可离身的重要物品，但是它的危害又有谁真正的注意过？

第一，手机辐射会危害到人的工作与睡眠。打个比方，你正在开会，忽然一个电话打断了正在讲重点的老总，你觉得他会认为你是一个专注工作的好员工吗？很有可能这个电话会断送了你的前程!很多人会在手机上下载一些游戏，更有的人为了玩那些所谓的游戏熬到3、4点还不睡觉；导致第二天精神不足，你觉得你还有精力做好工作吗？

第二，开车讲电话容易发生事故。据调查发生事故的几率是平常的两倍，这已经危害到了人的生命！人的生命是宝贵的，不该将它置于危险的边缘不是吗？

第三，公共场合打电话干扰了别人。例如，图书馆应该是安安静静的场合，如果这时一个电话铃声响起，你不会觉得不好意思吗？打扰他人学习是可耻的！尤其是在图书馆这种本该安静的地方!以及，课堂上老师正在授课，而你的手机铃声响了，你觉得老师会觉得他受到了他应有的尊重了吗？

第四，真假手机短信的泛滥造成了社会的安定动荡！色情短信的肆意转发，虚假短信的泛滥，造成了青少年的健康威胁以及社会的安定!

第五，手机的不断‘‘升级’’导致了攀比风的加重！明明承受不了还非要打肿脸充胖子！为家庭带了不必要的负担；更有的人为了不属于自己的虚荣卖器官，毁健康来买自己‘‘所需’’的东西!

第六，现在的孩子们都是小小年纪的就玩手机；我有一个5岁的小表妹，一天来我家做客，拿起妈妈的手机就要玩，这是一个习惯还是一种社会风气？引人深思!

以上种种危害都是现实中，我们身边都有的，而我们却不能及时制止！导致越来越多的大人、孩子都带上了眼镜！成了‘‘小四眼’’！

我在这里呼吁‘‘低头族’’：请你们收起手机去看看大自然的美丽，去关怀一下你身边的亲人，去关心一下自己的孩子收获亲情!

手机的危害演讲稿，尽在酷猫写作范文网。

第3篇 吸烟的危害演讲稿

演讲稿具有宣传、鼓动、教育和欣赏等作用，它可以把演讲者的观点、主张与思想感情传达给听众以及读者，使他们信服并在思想感情上产生共鸣。下面是小编为大家收集关于吸烟的危害演讲稿，欢迎借鉴参考。

吸烟的危害演讲稿

大家下午好!

'清洁空气，拒吸二手烟'是21世纪的第一个'世界无烟日'的主题，值得令人深思。

二手烟，也称为环境烟草烟，也就是指吸烟的人所呼出的气体和香烟本身燃烧时的烟雾的俗称。二手烟中包含4000多种物质，其中包括40多种致癌物质，吸进体内，亦可能和氡气的衰变产物混合一起，对人体健康造成更大的伤害。 美国最新一份研究报告指出,被动吸烟即吸'二手烟'比原先外界所知道的还要危险,在吸烟者吐出来的烟雾中，烟焦油和烟碱的含量，比吸烟者本人吸入的有害物质多出1-50倍。

'二手烟'危害猛于虎。据统计，目前我国被动吸烟的人数已经达到6亿人。其中有2亿人为未成年人。他们尽管自己不吸烟，但却无奈地吸入别人吐出来的、夹有大量卷烟毒性物质的空气。

有人认为只要通风好，在室内吸烟，对别人没什么影响。这种观点是错误的。烟草烟雾是发散、滞留在墙壁、沙发、地毯、家具的有害微粒(可吸入颗粒物)，它包含有重金属、致癌物、放射物质，吸烟者的衣服、皮肤、头发也都有残留。这些可吸入颗粒物可滞留数小时、数天甚至数月，不会随风而散。所以，单纯的开窗通风是没用的。所以请每一位吸烟者，请不要在别人面前吸烟，每一位不吸烟者都要有勇气和责任向吸烟者说：请到室外吸烟。

被动吸烟是一个重大的公共卫生问题，在我们的校园，有个别学生躲在厕所、寝室等地方偷着吸烟的现象也时有发现。学校为大家着想也对这些同学进行了批评教育。希望吸烟的同学到吸烟区吸烟，最好是努力战胜自己，早日戒烟成功。同时也希望大家引以为鉴，杜绝吸烟。

从全球范围看，公共场所禁烟时代已经悄然来临。截至20__年5月底，《烟草控制框架公约》缔约方共有147个国家，占世界总人口的80%左右。20__年1月9日，此公约在我国也已正式生效，20__年，我国已经对公众提供防止接触烟草烟雾的普遍保护。未来，'无烟城市'的打造会让我们生活的环境更加健康。

作为新时代的大学生。我们要时刻警惕吸烟的危害，坚决拒绝吸第一支烟，坚决拒绝吸二手烟，切实做好禁烟的宣传者和实践者，为把我校建设成为无烟学校、和谐校园而努力!

吸烟的危害演讲稿范文

老师们,同学们:

大家好!

相信每一个人都知道,烟草的危害是当今世界最严重的公共卫生问题之一,是人类健康所面临的最大的危险因素.目前全球烟民的总量已突破13亿人,每年因吸烟致死近500万人.为此,1987年11月联合国世界卫生组织建议将1988年的4月7日定为第一个世界无烟日,以后固定为每年的5月31日.开展这项活动,目的在于警醒世人吸烟有害健康,呼吁人们放弃烟草,为人类自己创造一个健康的生存环境.所有那么烟草究竟有多大危害呢

据研究,一支香烟里含的尼古丁可毒死一只老鼠,而约一包香烟中的尼古丁能毒死一头牛.每天吸一包香烟,相当于吸入了50-70毫克尼古丁,如果一次性地服用了这些量,人足以被置于死地.除尼古丁外,点燃香烟时产生的约5000种化合物,都是导致癌症的元凶.

世界卫生组织在今年发表的一项声明中指出:'如今烟草已经成为全球的第二大杀手.吸烟所产生的破坏比非典和最近的海啸还要严重.如果维持当前的趋势不变,到20__年,每年将有1000万人因吸烟而过早去世.'

既然烟草有如此可怕的危害,为什么有众多的人吸烟呢分析其原因主要有两个:一是烟草中所含的尼古丁令人上瘾,使人对它产生依赖,不容易戒掉;另一个原因是大多数人还没有把吸烟看成是一个丑陋的,既害人又害己的恶习.相反,认为这是一件很有派头,很潇洒的事情.因此,吸烟的人群像滚雪球一样越滚越大,人们对它的依赖也越来越强.

然而,烟草商们说:'我们生产的烟是给那些没有知识的人,年轻的人和愚蠢的人吸的.'我国是世界上最大的香烟生产国,也是最大的香烟消费国.全世界三分之一以上的香烟是由中国人一口一口吸掉的.而在我国的烟民中,青少年又占了很大的一部分.对青少年来说,吸烟的危害远比想象中大得多,不仅会导致很多疾病,还会影响骨骼生长发育.这是因为青少年正处于身体迅速成长发育的阶段,身体的各器官系统还没有发育成熟,对各种有毒物质的抵抗力不强,受烟雾的毒害也就更深,甚至可以导致早衰,早亡.吸烟还可能使青少年养成不良的生活习惯,诱发不良行为,甚至引发犯罪.反吸烟已成为我国迫在眉睫的当务之急.为此,我国政府提出了在今后20__年中,将我国的烟民总数减少1.1亿的总体目标.所有为了积极响应政府的号召,更为了我们自己的健康,我们呼吁,全体同学都要自觉地远离香烟,并劝说吸烟的亲友尽量戒烟.毕竟,香烟对我们有害无益;毕竟,没有烟雾的空气会更加清新,没有烟草的生命会更加绚烂!

吸烟的危害演讲稿1000字

各位评委，各位同学们大家好，我是来自设备工程系供热g132的曹嘉恒。

众所周知，烟草危害是当今世界最严重的公共卫生问题之一，全球每年因吸烟致死的人高达600万人， 但是如果你指望我提醒你，吸烟是多么有害健康，多么浪费金钱，多么肮脏下流，多么愚蠢，多么不可救药，那我恐怕要让你失望了。因为在咱们国家控烟的宣传并不少，铺天盖地的广告，和何种形式的公益活动，至今也没有停下过。 但是吸烟的情况还是不见衰减，所以说如果这些话就能帮吸烟者摆脱烟瘾的话，也许咱们国家早就戒烟成功了。但是我还是希望我今天的演讲能过为我国控烟贡献出一点力量，真正能让吸烟者戒烟。所以说今天我演讲题目是《拒绝吸烟，还生命一份明净》 跟大多数人认为的不一样，吸烟者并不是自主选择吸烟的，正如酗酒者不是自主选择酗酒，吸毒者不是自主选择吸毒一样。你最初的选择，只不过是尝试一下吸烟的感觉而已。

许多人都会尝试去电影院的感觉，却从来没有人一辈子泡在电影院里。 所以说其实所有吸烟者掉进了一个险恶的陷阱，这个陷阱是由人类和大自然共同构建的。 我们为什么会在青少年时代掉进陷阱?因为有无数的成年人已经掉了进去。他们不是没有警告过我们， 吸烟是一种恶心的习惯，不仅浪费金钱，最后还会要了我们的命;然而我们却把这样的警告当成耳边风，认为他们一定是把吸烟当成一种享受。吸烟的荒谬处之一就 在于，要“学会”吸烟、染上烟瘾，其实并不是一件容易的事。 这个陷阱里并没有任何诱饵，我们并不是因为吸烟感觉良好才掉进去的，事实上第一支烟的感觉必然十分糟糕。如果第一支烟感觉良好，或许我们头脑里就 会响起警钟，我们会意识到陷阱的存在。然而正因为第一支烟的感觉无比糟糕，我们才会以为自己绝不会染上烟瘾，在不知不觉中一步步走进陷阱。 吸烟这件事情仿佛是一座巨大的迷宫，我们一进入迷宫内，头脑就会变得糊里糊涂，尽管努力寻找，却总也找不到迷宫的出口。有些人幸运地找到了出口，却莫名其妙地再次误入。 寻找出口的过程有人花了5年有人花了20__年，有人则花了30年。

所以说，如果你现在是一个非吸烟者，请不要去尝试吸烟，因为社会风气正在转变，所有的吸烟者都感到迷茫。越来越多的人讨厌吸烟，包括吸烟者自己。数百万吸烟者已经成功戒烟，所有的吸烟者都在考虑戒烟。每当一个吸烟者脱离陷阱，剩下的吸烟者就会更加痛苦。他们心里很清楚，用来之不易的金钱购买卷在纸筒里的干烟叶，点燃之后塞在嘴里，把致癌性的焦油和其他剧毒物质吸入肺部，这一切是多么荒唐。吸烟者无法为吸烟行为做出理性的解释，吸烟者总会为他们的“习惯”而说谎，不仅欺骗他人，也欺骗自己。他们不得不这样做。如果他们仍然想保留自尊，就必须对自己进行洗脑，必须为吸烟这种肮脏的“习惯”找寻借口。他们要欺骗的不仅仅是自己，还有所有的非吸烟者。所以，他们总是在宣扬吸烟的“好处”。但是他们本身还是希望尽早脱离吸烟行列。

所以说，中国控烟的大环境在改变。我们知道吸烟会导致死亡，但也知道仅仅一支烟不会。社会上还有那么多吸烟的人，而青少年的模仿能力又是如此之强。我们作为现当代大学生，一定要认清局势，这个陷阱千万不要跳进去。跳进去几年之后 痛苦我也许不单单是你自己，所以说从今天开始拒绝吸烟，还生命一份明净。我的演讲到此结束。

谢谢大家!

第4篇 手机危害的英语演讲稿

手机危害英语演讲稿

good morning, ladies and gentlemen. i’m contestant no._, zhai weiwei.i feel really honor to stand here and make a speech.today i’m going to look together with you in to this question: does modern technology make the interpersonal communication better?

have you ever found that there’s one word we use more frequently nowadays? the answer is-awkward. if you do not believe, please imagine this scene. sunlight floods the earth. the spring breeze is warm and gentle. you’re finally going to meet the one that you usually talk with on the internet. but when it really comes to face to face conversation, you will find it really hard to raise a topic and keep it going. how you wish you two can use wechat even he or she is just in front of you! it just like someone in your mind keeps shouting that it is so awkward!

you are addicted to the virtual world and escaping from the reality. some people call this phenomenon as embarrassing cancer. it is funny, but it is really happening around us. such an issue would like the virus spread to every aspect of interpersonal communication. we began to avoid family party, put on headphones to avoid caring, send massages to someone behind the screen, ignoring the people around you. abandoning yourself to the so-called personal space. gradually, walls between people will be built one after another. walls that we, and even our children, cannot go beyond.

i believe mu_in once said,' days were slower in the past. carriage, horse, and mail did not reach fast. you need your lifetime to just love the person who is right.' but now, the world has changed. when you want to strike up a conversation with a girl, you don't need to hide in somewhere, wondering what to say will make her happy. you just need to pick up your phone and search for nearby people without hesitation. flood of emotion swept over us, leaving only emptiness after ebbing. emotions lack the process of precipitation, becoming impetuous and cheap. if things go on like this, people will ignore the value of emotion, being a slave of modern technology.

of course, i do not want people to return to the primitive society. in my opinion, we need modern technology, and there is no doubt that modern technology will play an important role in our communication. in fact, we should make use of it rather than relying on it. therefore, what we should do is not stubbornly stick to a small circle, but look at the world, look to the future.

ok, that's all of my speech, thanks for your listening.

手机危害英语演讲稿

good evening ladies and gentlemen! i am chen yanrong.

today,i would like to take this opportunity to share my perspective about the influence of science and technology. science and technology sounds abstract but it can be seen almost everywhere in different concrete forms,such as the lamps above your head, and the cellphones in your hand .above all,the most closely associated form with our life is the internet ,of course.

as for me ,i have deeply felt the charm of the internet . my best friend went aboard for further study two years ago . at the begining,i didn't get used to that and therefore suffered from melancholy,tossing and turning late at night,missing her terribly.fortunately, my spirits didn't sink for too long as it suddenly occured to me that why don't we keep in touch through the internet? by sharing wechat moments and using video calls ,we didn't drift apart, but became closer instead. even though we are tens of thousands of miles apart, i feel like she's always by my side.

science and technology not only establishes a bridge of communications between friends ,but also offers a broad platform where we can freely e_press ourselves and maybe resonate with people we've never met before.whenever you find your life unsatisfying,on the internet,there 's a free world for you to place your lonely soul. what's more ,we get information through science and technology beyond limitations of time and space.that's why people can unite as one to offer timely help whenever disasters strike.

as it walks into tens of thousands of households,sience and technology has effectively shortened the distance between people .but i believe some of you are not in favor of this viewpoint ,right?maybe you think science and technology is the chief culprit that makes the distance between people's hearts farther and farther,since more and more people are getting network addition,paying too much attention to the virtual world rather than people and things around them. from my point of view ,however,science and technology is not to blame,because what kind of influence it brings into our life depends on how we make use of it. it's as plain as the nose on your face that science and technology does offer us better conditions to bring us together , but we should also keep in mind that only by reflecting on how to use it properly can we fully enjoy the charm of science and technology.

science and technology surrounds and sustains us in the world, making the earth more like a small village where we breathe together ,laugh together and watch the starry sky overhead shoulder to shoulder.

第5篇 网络的危害演讲稿

在一个人的成长与发展过程中，青少年时期至关重要，承载着个体身心急剧发育并趋近成熟的重责。而从一个国家、一个民族的发展来看，青少年群体意味着未来。个体需要健康的心理陪伴一生，国家也需要心理健康的公民延续希望。

作为新兴的工具和信息传递手段，网络以其快捷的速度、广泛的内容、开放的环境以及多样化的功能而受到大众的喜爱。网络正在日渐普及的同时悄然影响着人们的生活，而青少年更是网络最为活跃的使用者。据中国青年政治学院教授陆士调查指出，目前，网络参与者的80%以上都是青少年。除了享受到网络带来的便利，青少年同时也面临着网络低俗信息带来的巨大诱惑和威胁。

根据国际上比较宽泛的一种分类，青少年指年龄为9～19岁的人群，恰好包含了我国的中小学多个年级的学龄少年。为什么说青少年是受到网络低俗信息危害最大的潜在群体？网络低俗对青少年的心理有什么危害？答案就在青少年身心发育的特点中：

1网络低俗钻了青少年认知能力相对不成熟的空子

青少年具有强烈的好奇心与求知欲，但由于身心发育处于趋近成熟的过程而非达到成熟，以及人生阅历的局限，其认知、思维能力与成年人相比，还不够成熟。特别是处于青春初期的少年，对于网络上的一些低俗信息难以作出较为理性的判断和分析，常常以自己的直觉或者相对浅显的社会经验进行简单判断、作出取舍。有时不免会把其中的某些低俗行为引为时尚而在同伴中炫耀，不仅自身受到低俗侵袭，还会让身边的`伙伴连带受到不利影响。有时，青少年会迷失现实与虚拟的界线，在心理上，失去对有危害行为的警戒线，在危害自身健康的同时甚至发生犯罪行为。事实上，即使是成年人，当面对网络上入浩瀚烟海一般的各种信息时，也难免会做出不合理的价值分析和判断。更何况是这些还在求知阶段、价值观尚不成熟的孩子。

2网络低俗迎合了青少年逆反期的独立意识

青少年独立意识增强，又正值“第二逆反期”。网络上一些不被允许的行为正好迎合了他们反叛、追求个性的要求。事实上，低俗信息通常与传统的价值观相违背，且比较刺激，因此即使知道某些信息会有不好的影响，但为了彰显自己的独立性，引起更多的关注，有些青少年还是会沉溺其中，从而习得混乱的价值观，并对不良行为失去判断力。

3网络低俗异化了青春期的成人感

处于青春发育期的青少年体验着身体外形的巨变、体能的增强、性器官及其机能的逐渐成熟，加上智力的飞跃发展，使得他们认为自己“已经长大成人”，并迫切希望得到成年人的认同，如表现得关注成年人的信息，甚至在对结果估计不足之前已接受并模仿成年人的行为。网络中黄色、暴力等低俗信息给青少年以“成人化”的误导，容易诱发青少年盲目模仿，严重者违法犯罪，使成长不能承受之重。

4网络低俗误导青少年的性能量

由于性器官及其机能的逐渐成熟，青少年正处于性心理发育的关键时期。身体的发育使他们对于性充满好奇和渴望，而网络低俗往往扭曲、夸大人类性行为，传播着不科学的性信息，可能诱使青少年发生性过失的行为，这将影响他们未来在恋爱、婚姻中的性心理健康水平。需要指出的是，当青少年在网络中与性方面的信息“不期而遇”或者自发搜寻性知识时，自己不必心存羞耻或罪责感，因为探求性知识是性发育正常的表现之一。但是应该认识到低俗的性信息对自己的性心理发育百害而无一利，要自觉地从健康的网站、书籍或音像制品中求取科学的性知识；二是遭遇低俗的性信息之后应向网络管理机构举报，并最好向学校的心理辅导老师或其他可信任的长辈倾谈或求助。

5网络低俗虚掷了青少年的生命活力

青少年的自我约束能力相对成年人较弱，低俗信息通常与学业无关，但却有极大的诱惑力，因此容易诱发青少年的不良兴趣爱好，耗费其大量时间和精力，干扰其正常的学习和人际交往，不利于其社会适应性的发展。此外，青少年的心理闭锁倾向比较严重，即遇到困难或困惑时不愿意对成年人暴露自己的内心和焦虑，不习惯向身边的师长倾谈和求助，因此得到帮助的机会甚微，当遇到难以解决的问题且不能承受时容易出现极端行为。

鉴于这一群体的身心发育的特殊性，与成年人相比，青少年更容易在虚拟与现实之间迷失方向，更容易被网络低俗侵蚀和伤害，更需要相对纯净的网络环境，期望青少年朋友加强对自身成长规律、对网络低俗的认识，树立“身体健康、道德健康和心理健康”的现代健康观，提高警惕，养成良好的上网习惯，自觉远离网络低俗信息；形成积极正向的兴趣爱好，在健康的文体活动中强健体魄、丰富心灵。而作为青少年成长中的重要他人，家长宜多与青少年进行沟通，关注并重视青少年在现实世界中的人际交往与业余活动。此外，愿与学校心理健康教育同仁互勉，让我们继续及时且有效地普及青春期心理健康知识，给予青少年心灵上专业支持与成长中的陪伴；引导青少年自我教育、同辈辅导，提高辨析能力和抵御诱惑的能力；做好个体心理咨询与团体心理辅导工作，尽己所能，与社会各界共建网络晴空。