By the time he was twelve, Edison ________ to make a living by himself .
| A．would begin | B．has begun | C．had begun | D．was begun |
______ from their parents for half a year, the students couldn’t wait to go back home.
| A．Separating | B．To be separated |
| C．Having separated | D．Having been separated |
The apartment we’ve recently rented ______ six rooms in all, the largest of which serves as the sitting room.
| A．consists of | B．is consisted of |
| C．made up of | D．consisting of |
Lily doesn’t work in the same school as me, but we ______ at the same college for four years.
| A．study | B．studied |
| C．have studied | D．had studied |
The death of his devoted son was a painful experience, ______ he had never fully recovered.
| A．from which | B．from whom |
| C．with which | D．with whom |
Only after David was asked to pay more attention ______ repeating the same mistake.
| A．he avoided | B．did he avoid |
| C．had he avoided | D．he had avoided |