It seems oil _____from this pipe for some time, we’ll have to take the machine apart to put it right.
| A．had leaked | B．is leaking | C．leaked | D．has been leaking |
That they were wrong in these matters ____ now clear to us all.
| A．is | B．was | C．are | D．all |
Large quantities of water ____ for irrigation.
| A．is needed | B．has -needed | C．are needed | D．need |
Between the two rows of trees ____ the teaching building.
| A．stand | B．stands | C．standing | D．are |
I have finished a large part of the book, the rest of which___ more difficult.
| A．is | B．are | C．was | D．were |
The whole class ____ the teacher attentively.
| A．are listening to | B．is listening to |
| C．are listening | D．is listening |