题干

据科学家预测,月球的土壤中吸附着数百万吨的32He,每百吨32He核聚变所释放的能量相当于目前人类一年消耗的总能量.在地球上,氦元素主要以42He的形式存在.下列说法正确的是(  )

A:42He比32He是同种原子的不同表示形式

B:32He和42He互为同位素

C:32He原子核内含有2个中子

D:42He与32He的质量数相等

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答案(点此获取答案解析)

B

同类题3

在短文的空格内填入适当的词,使其通顺。每空格限填一词,首字母已给。

    "Olyvia, love is simple. You don't have to do much to make someone happy. "That was what my mother said to me when I was a child. Over a year ago, I had a chance. My good friend Kaylee told me about her t____ to a small town called Gary, and how it was a life-changing experience. I made up my mind to go there myself.

    When I told my parents about the decision, they didn't a____ at first. They said I didn't know much about the place. They were worried that it was not s____ for me to go there. Thankfully, after I explained my plan to them in detail, they said yes.

    When our group arrived in Gary, I noticed how different the town was from where I lived. There were few stores or restaurants in the town; most had closed. So you would be very l____ if you could find a place to buy food or drinks. Houses were built on small hills. Many of them had broken doors or windows. My job was to help the local people to r____ houses.The work days were long and hot, but it was really good to see the houses taking on a new look day by day.

    The children there were also different. They seemed to enjoy every moment in life though they were poor. The smallest things would make these kids happy. I couldn't find words to describe their j____ when they received an ice-cream, a ball or even a kiss. The community was like a big family. Everyone knew each other and was there when someone needed help.

    I am so glad that I had this unforgetable experience. I truly learned the m____ of what my mother said. You don't need to do much to make a difference to others' lives.

同类题5

阅读下面语段,回答问题。

       ①自从党中央倡导节约以来,全国人民积极行动,从“光盘”行动开始,节约的资源量已经形成了一组可观的数字。例如,我们每年在餐桌上节约的脂肪量预计可达800万吨,相当于1500万吨大豆的油脂含量,这样每年就可减少1000多万吨的大豆进口,所以,我们每一个中国人都应从餐桌开始节俭。节俭是一种美德。

       ②我国人民历来崇尚节俭,先辈们在创造了灿烂文明的同时,也从历史的变迁、世事的兴衰中认识到了节俭的必要性。从提出“情而侈则贫,力而俭则富”的管仲到告诫“节俭则昌,淫逸则亡”的墨子;从主张“强本而节用,则天下不能贫”的荀况到写下“历览前贤国与家,成由勤俭败由奢”的李商隐;从《朱子家训》到曾国藩家书,这些都说明了节俭是一种美德。

       ③节俭有助于一个人修身养性、陶冶情操,也是一个人事业有成、持续发展的重要因素。诸葛亮的“静以修身,俭以养德”说的就是这个道理。过着洁白朴素的生活,与人无求,于己无愧,不为物欲所羁绊,就可以把人的整个身心投入到追求的事业中去;反之,穷奢极欲、挥金如土的生活中永远不会产生崇高的理想和艰苦创业的精神。古语有云:“自古纨绔少伟男”,纵观古今,凡是通过艰苦奋斗取得突出成绩的人,都拥有节俭这一美德。

       ④一个人的发展离不开节俭,一个国家的繁荣昌盛同样与节俭息息相关。老一辈无产阶级革命家***一直以来都倡导全国人民勤俭节约,他曾说过:“贪污和浪费是极大的犯罪”。当前,党中央号召全国人们厉行节约,反对浪费。实现中华民族伟大复兴的中国梦,更离不开节俭。这些无不表明节俭的重要性。

       ⑤其实,厉行勤俭节约,反对铺张浪费,不能止于餐桌,更不能仅仅限于一时,还需要以更加宽泛的视野、更高层次的眼界,在思想上,在每一个人的生活细节上,来一次意义深远的社会改良。在建设社会主义精神文明的今天,我们有责任继承“节俭”这一中华民族传统美德,并将这种美德发扬光大。

(原文有改动)