阅读下面材料，在空白处填入适当的内容（1个单词）或括号内单词的正确形式。
Dear fellow students,
May I have your attention, please? Now I’d like to make a speech here. As we know, waste _1. (become) common scenes on campus. Some pour the remains of a meal when there is still much 2._(leave); 3._ simply walk away after washing hands, leaving the water _4._ (run); students leave the classroom every day 5._ noticing whether fans are switched off. Has thrift(节俭)，one of the most national tradition 6. developed from our long history gone? 7. so, find it back!
We don’t have to take great pains to control waste, but action and a grateful heart are needed; thank the water that runs through our fingers, and save it for poor Arabian or African countries struggling in water 8. (short); thank the light we enjoy because in poor areas, children share a dim(昏暗的) lamp 9. (read); thank all the paper we are able to use, for trees are cut down to satisfy _10._ needs; thank everything nature can offer and everything we can own.
Live and act, so the tradition of thrift will never fade.
You had better book rooms at the hotel in advance you should find no room on your arrival.
A. so that B. even if
C. in case D. now that
____ you call me to say you are not coming, I will see you at the theatre at five this afternoon．
A. Though B. Whether
C. Unless D. Until
We need some more facts and figures ______ we make the final decision.
A. since B. before
C. after D. until
She says that she’ll have to close the shop ________ business improves.
A. if B. unless
C. after D. when
The family were holidaying in the country _______ the rain poured down.
A. when B. as
C. while D. since
