I ____ in the street when I met an old friend of mine the other day.
| A．walked | B．was walking | C．has walked | D．had walked |
There was ______ time ______ I hated to go to school .
| A．a; that | B．a; when |
| C．the; that | D．the ; when |
He made another wonderful discovery, ______ of great importance to science.
| A．which I think is | B．which I think it is |
| C．which I think it | D．I think which is |
When they met again, the two friends talked about lots of things and persons ______.we could remember in the school.
| A．who | B．whom | C．that | D．which |
The factory ______ I am going to is the place ______ my mother used to work many years ago.
| A．where, where | B．where, which |
| C．which, where | D．that, which |
Who can pwhat life will be like in the future?