His experiment done in ______ summer of 1970 was ______ failure.
| A．/; a | B．/; / | C．the; a | D．the; / |
— How long do you think it will be _______ the USA recovers from the losses of the financial crisis?
— Perhaps four or five years.
| A．when | B．since | C．that | D．before |
Listening attentively in class and reviewing in time _______ a sure way to improve your learning, and this is especially true _______ it comes to standard tests.
| A．are; when | B．is; when | C．is; while | D．are; as |
Though the teacher had tried to make the problem easy _______, still Lily and her partner were at a loss.
| A．understood | B．understanding | C．to understand | D．to be understood |
_______ difficult the task may be, we must finish it on time, because we can’t miss _______ a precious opportunity．
| A．Whatever; so | B．However; such | C．However; so | D．Whatever, such |
— Bad luck. They didn’t offer the job to me.
—_______ You’ve been well prepared for the interview.
| A．So what? | B．What if? | C．How come? | D．Guess what? |