___________ certain that his invertion will lead to the development of production.
| A．That’s | B．This is | C．It’s | D．What’s |
The experiment turned out to be______failure, but “_________failure goes before success”
A a , a B /, / C a , / D / , a
Was it because his mother was ill ______ he didn’t go to school?
| A．so | B．that | C．why | D．when |
Our teacher asked us to give all the used books to ______ needed them.
| A．all | B．whom | C．those | D．those who |
We have got plenty of time. We ______ hurry.
| A．needn’t | B．mustn’t | C．shouldn’t | D．cannot |
—Do you mind if I keep pets in the building?
—______.
| A．I’m afraid you can’t | B．Of course not, it’s not allowed here |
| C．Great! I love pets | D．No, you can’t |