Steps must be taken ________ this kind of disaster will never happen again.
| A．because | B．even if | C．as | D．so that |
The children were playing games on the playground, ________ school uniforms.
| A．all of them wore | B．all wearing |
| C．all of whom wearing | D．all were wearing |
It is written clearly in the requirements that all passengers ______ check onto board 30 minutes before the plane takes off.
| A．may | B．can | C．will | D．shall |
—I failed again. I wish I _________ harder.
—But you _________.
| A．had worked; hadn’t | B．worked; don’t |
| C．had worked; didn’t | D．worked; didn’t |
Drunk driving used to occur _______, but now it is under control.
| A．generally | B．frequently | C．practically | D．gradually |
It gives his life a flying start ______ he has gone abroad for further education.
| A．what | B．when | C．that | D．how |