When he was alive, the old scientist used to say that knowledge ______ from practice and he gained his experience by doing a lot of practical work.
| A．was coming | B．had come |
| C．comes | D．would come |
Samuel was _____ why few of his friends attended his birthday party.
| A．spotted | B．crashed | C．puzzled | D．limited |
_____ life exists on any other planet in the solar system still remains a question.
| A．Why | B．Whether | C．How | D．Where |
Later, the naughty boys _____ to the English teacher for having played a trick on her the other day.
| A．apologized | B．introduced | C．reminded | D．stared |
The company is deep in _____, so you’d better avoid dealing with it.
| A．benefit | B．thought | C．debt | D．strength |
—I met your uncle on my way to school this morning.
—Ah? You _____ be joking. He flew to Germany yesterday evening!
| A．might | B．should | C．could | D．must |