--How long ___________ each other before they__________ married?
--For about a year.
| A．have they known;get | B．did they know; were going to get |
| C．do they know;are going to get | D．had they known; got |
He wrote the article ____ three days.
| A．at | B．in | C．on | D．by |
He will return____ three o'clock.
| A．after | B．in | C．on | D．at |
He went to Beijing and returned ____ three days.
| A．in | B．before | C．later | D．after |
He will come ____ three days.
| A．before | B．after | C．in | D．later |
The PLA man saved the boy ____ death.
| A．of | B．from | C．to | D．on |