单句语法填空
【小题1】People should be encouraged ________（use）public transport, as it can reduce pollution.
【小题2】I am not only very careful in spending money, but also studying hard to live up to my parents' ________（expect）.
【小题3】To avoid ________（waste）electricity we should not keep the lights on when there is enough light in the classroom.
【小题4】In cities cycling to and from work is not only a ________（reason）way for people to reduce the traffic jams but also a good way to keep fit.
【小题5】While the ________（major） of people you will meet when you are travelling are sure to be friendly, there are also impolite and dangerous ones.
【小题6】He doesn't owe his success ________ luck but ability.
【小题7】________（brief）speaking, English is so useful that all of us students should learn it well.
【小题8】At his humorous joke, all the people present burst into ________（laugh）.