题干

高空坠物可能造成严重的人体伤害,下列描述正确的是(  )

A:高空坠物的动能会转化为重力势能

B:物体若没有坠落,就没有能

C:空中坠物的重力势能会转化为动能

D:物体坠落到地面时具有很大的重力势能

上一题 下一题 0.0难度 选择题 更新时间:2015-11-20 09:11:31

答案(点此获取答案解析)

C

同类题3

阅读下文,回答问题

和影子伙伴一起长大

    ①女孩子的青春期几乎都会和一个男生有关,因为脆弱而敏感的女孩子需要一个如影相随的伙伴给自己的成长加油鼓劲。坚忍而率真的男孩往往就充当了这样的“影子伙伴”。

    ②小娅是一中的择校生,一个沉默而自卑的女孩。上物理课,她把脑袋枕在胳膊上打瞌睡。迷迷糊糊中,她看到对面30度角的地方有个笔直的身影“刷”地站了起来,掷地有声地回答问题。她咯噔了一下,脑袋狠狠地撞击了一下桌面,睡意全没了。她摸着生疼的额头,忍受着来自四面八方的目光和嘲弄的笑声。笔直的背影却始终没有偏离一度,他也许根本就不屑于嘲笑小娅,所以连看她一眼的兴趣都没有。

    ③他叫凉茶,直升进了这所历史悠久载誉无数的全国重点中学。凉茶习惯光脚穿球鞋,凉茶做难题时喜欢咬自己的胳膊,凉茶从来不吃冷饮,凉茶专门在校门口的书报摊买《体坛周报》,凉茶骑的车喀嚓喀嚓每个零件都在歌唱……

    ④小娅买了一本笔记本专门用来记录凉茶的每个细节,着了魔似的。可凉茶笔直的身体从未朝她倾斜半度,眼珠始终没有在她身上停留过半秒。

    ⑤也许她真的是一个非常平凡的女孩,她有点沮丧。

    ⑥高一下学期,小娅带着“好玩”的态度参加了全国性的作文大寒,运气好的不得了,她居然获得了一等奖。那天刚进校门,小娅就看到凉茶正在自己的喜报前驻足,她兴奋得心都快从嗓子眼儿里冒出来了。他终于留意到自己啦,乌啦啦乌啦啦,她决定马上跑回去把这一刻记在她的小本本上。可是一转身,她摔倒了,左脚绊了右脚,就在她倒下的一瞬间,有双手扶住了她,是凉茶。她原以为自己会幸福得晕过去,可是她清醒得很,还闻到了凉茶身上刺鼻的狐臭味。

    ⑦从此小娅没有再为凉茶记录只字片语。

    ⑧每个女孩子的青春日记中都会出现一个男生的形象。也许是常常保护你不被欺负的邻居大哥,也许是班上成绩最好的同学……刹那间你被击中,然后他开始频繁地出现在你的日记里,他的微笑他的转身甚至他静止的背影都让你深深迷恋。在你远远观望下,他是一个十足完美的人,简直就是天使的化身。

    ⑨可是有一天,你走近了他,你会发现:他也许会在公共场合抠鼻子,他吃肯德基喜欢舔手指,他不给老弱病残孕让座……他的完美形象轰然倒塌。其实他本来就这样,只是你从前都没有留意到。当你觉得他们不再完美,甚至开始厌恶他们时,那一定是因为你长大了,你不再需要影子伙伴,你相信自己是最棒的,你已经积聚了足够的力量选择一个人坚定地走下去,走出一道美妙的独行风景。

(摘自新西兰《中文先驱报》;作者:佚名)

同类题4

阅读理解

    La Tomatina, Spain

    Tomato juice flows through the streets of Bunol on the last Wednesday of August as the worlds largest tomato fight happens. Festivities begin in the town square where there is a huge pole covered in soap and with a leg of ham at the top. Participants try to climb up the pole to get the ham as watchers throw buckets of water to them. After a gun is fired to signal the beginning of the fight, people catch the tomatoes and throw each other in the streets until the gun sounds again, marking the end of the event.

    Holi, India

    This spring festival is celebrated throughout the country in late February or early March. The two-day event celebrates the legend of Prahlad, who escaped unharmed from the fire of the evil Holika Dahan. People mark the event by lighting fires and throwing colored powder on one another Children load colored water into toy pistols called pichkari and take aim at passers-by. Holi is known as a happy celebration of the victory of good over evil.

    Burning Man, Nevada

    This infamous festival began in 1986 with the burning of a large figure to mark the summer solstice (夏至). It's since grown into a week-long annual event that draws more than 48,000 people to the Black Rock Dessert. It is held during the week before Labor Day. Participants set up camp in the desert to celebrate art.

    Songkran, Thailand

    This festival marks the Thai New Year, which is celebrated in the second week of April. This is the hottest time of the year in Thailand, so it makes sense that the biggest Songkran tradition is to throw water on people. Thais of all ages join in water fights, using buckets, hoses (软管) and water guns to celebrate the event.