The computer centre, ______ last year, is very popular among the students in this school.
| A．open | B．opening |
| C．having opened | D．Opened |
Please go on trying, I’m sure the efforts you are ________ will pay off.
| A．doing | B．giving | C．making | D．sparing |
–Who is the man talking to the headmaster?
–A professor ________ a visit to our school.
| A．pays | B．is paying | C．paid | D．paying |
Scientists found many stones ________ with numbers on the mountains.
| A．marking | B．marked | C．being marked | D．have been marked |
–The plane is due to take off at 7:50 from the airport.
–________ we fail to arrive there in time. –Try to take another flight then.
| A．What if | B．As if | C．Even if | D．Only if |
–I’d like to buy a new CD player. –Well, we have several models ________.
| A．to choose of | B．to choose from | C．to be chosen | D．for choosing |