China's high-speed railways _________ from 9,000 to 25,000 kilometers in the past few years.
| A． |
are growing |
B． |
have grown |
C． |
will grow |
D． |
had grown |
He asked me how much ____ on the mountain bike.
| A．did I pay | B．I paid |
| C．had I paid | D．I had paid |
I haven’t finished my report, but I promise I ____ it by the end of the week.
| A．will finish |
| B．have finished |
| C．will be finishing |
| D．will have finished |
—Haven’t seen you for ages! Where have you been?
—I went to Ning Xia and ____ there for a year, teaching as a volunteer.
| A．stayed | B．stay |
| C．had stayed | D．am staying |
“It’s too early to conclude that the problem ____ but I think we have been moving in the right direction,” the manager said
| A．had been solved | B．had solved |
| C．has been solved | D．has solved |
I haven't finished my composition. I ____ for two hours and a half.
| A．have written it |
| B．have been writing it |
| C．wrote it |
| D．am writing it |