Exactly ____they did when at last they reached the sea remains a complete mystery.
| A．that | B．how | C．which | D．what |
Low-carbon lifestyle is of great benefit to the world environment. However, ________ can be enjoyed from it until you have a deep understanding of it.
| A．something | B．nothing | C．few | D．much |
Julia was very sad over the loss of the photos she had shot at Canada, _________ this was a memory she especially treasured.
| A．as | B．if | C．because of | D．where |
My mother ________ always wave goodbye to me while I was leaving for school.
| A．should | B．must | C．could | D．would |
Faced with the crisis(危机), the government _________ calm and took timely measures.
| A．grew | B．appeared | C．became | D．stayed |
In autumn, leaves turn yellow and _________ the trees.
| A．fall out | B．fall off | C．fall down | D．fall over |