Sheldon could have defeated Howard in the match, but he _______ too careless at the last minute.
| A．is | B．was | C．has been | D．had been |
Although he was in poor health, Robert succeeded other more famous engineers failed．
| A．which | B．that | C．what | D．where |
You can eat food free in my restaurantyou like.
| A．whenever | B．wherever |
| C．whatever | D．however |
—when has the country been open to international trade? —1978，I suppose.
| A．Since | B．In | C．From | D．After |
With the rapid growth of population, the city ____ in all directions in the past five years.
| A．spreads | B．has spread |
| C．spread | D．had spread |
----I wonder if you could go with me to the cinema.
----Don’t disturb me. I ____ a composition all the morning and haven’t finished yet.
| A．write | B．was writing |
| C．have written | D．have been writing |