完成句子（共10小题；每小题2分，满分20分）
阅读下列各小题，根据汉语提示，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。
71、Be careful when you deal with this chemical，as it will explode when __________________. (expose)
处理这种化学物质时要小心，因为它暴露在阳光下时会爆炸.
72、Nowadays young people just can’t live without the Internet, _______________for whatever information they need. (depend)
如今的年轻人离开因特网就无法生活，他们依靠它获取自己所需信息.
73、A hobby is what you never get tired of — ____________________, the more fun you will have. (devote)
爱好是不会让你感到厌倦的—你投入的时间越多，获得的乐趣越多。.
74、So______________________________ on the phone that we knew there would be good news.(voice)
他的声音在电话中听起来如此地激动，以至于我们都知道会有好消息.
75、Part of the reason why he is absent is , I think, that he __________________the meeting.(inform)
我想他缺席会议的部分原因是他可能没被通知.
76、___________________________________, professor Smith went straight to the laboratory to continue his experiments.(have)
理完发后，Smith 教授径直到了实验室，继续他的实验.
77、Whatever you have picked up, you should give it back to_____________________.(belong)
无论你捡到什么东西，你都应该物归原主.
78、Her father gave her advice on learning English _________________________________as much as possible.(employ)
她的父亲建议她学英语时尽可能多用它.
79、We are designing an experiment to find out if __________________________________ when it is cold.(break)
我们正在设计一个实验，想弄清楚当天冷时，玻璃是否更容易破裂.
80、_____________________ she is not so cheerful as she used to be?(why)
她没有以前那么高兴究竟是为什么呢？
知识点：翻译
完成句子：
71. (it is) exposed to the sun/sunlight/sunshine
72.on which they depend / which they depend on
73.the more time you devote to it
74.excited did his voice sound
75.may/might not have been informed of
76.Having had his hair cut/ After having( had) his hair cut / After he (had) had his hair cut
77.whoever it belongs to
78.that she (should) employ it
79.glass breaks more easily/glass is easier to break
80.Why is it that
略