问题 选择题

下列气体既可以用浓硫酸干燥,又可以用固体氢氧化钠干燥的是(  )

A.SO2

B.NH3

C.Cl2

D.O2

答案

A.二氧化硫是酸性气体,能与氢氧化钠反应生成亚硫酸钠和水,不能用氢氧化钠干燥,故A错误;

B.氨气是碱性气体,与浓硫酸反应,生成硫酸铵或硫酸氢铵,不能用浓硫酸干燥,故B错误;

C.Cl2是酸性气体,能与氢氧化钠反应生成氯化钠、次氯酸钠和水,不能用氢氧化钠干燥,故C错误;

D.氧气是中性气体,既不与浓硫酸反应,也不与氢氧化钠反应,因此可以干燥,故D正确;

故选D.

完形填空

阅读下列各小题,根据括号内的汉语提示,用句末括号内的英语单词完成句子,并将答案写在答题卡上的相应题号后。

小题1:With so much work on hand, you                            to see the movie last night. (go)

手头有这么多工作,你昨晚本不应该去看电影的。

小题2:I hear your new boss is not                            , so you should be more careful. (get)

听说你的新老板不容易相处,因此你应该更小心些。

小题3:You have no idea                             during the last few months, which has affected me for a long time. (go)

你不知道在过去的几个月里我经历了些什么, 而这些影响了我很长时间。

小题4:Excited by his move to London, John                             begin his new life. (wait)

约翰因为要搬到伦敦去而激动不已,迫不及待要开始他的新生活。

小题5:                           of the skill, you will find it easier to solve such problems. (once)

一旦你掌握了这门技能,你会发现解决这些问题更容易。

小题6:She was                             when her daughter didn’t come home on time. (more)

她女儿没有按时回家时,与其说她生气倒不如说她担心。

小题7:He expressed his gratitude to his head teacher, without                            , he wouldn’t have made such great progress in his studies. (help)

他向他的班主任表达了感激之情。没有他的帮助,他不可能在学习上取得这么大的进步。

小题8:This is the second time that he                             for speeding this month. (fine)

这是他这个月第二次因超速而被罚款了。

小题9:But the one million people of the city,                             these events, were asleep as usual that night. (think)

但是,唐山市的一百万居民几乎没有把这些情况当回事,当天晚上照常睡着了。

小题10:Was it on a lonely island                             one month after the boat went down. (save)

他是不是沉船一个月之后在一座孤岛上获救的?

填空题