I don’t remember how many years ago _____ I was taken to Beijing for the first time.
| A．it was when | B．it was that |
| C．was it that | D．was it when |
She wrote a letter to her father, ___ she made her secret known.
| A．which | B．that | C．in which | D．where |
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 |
The last river __ _ they crossed is two miles wide.
| A．where | B．which | C．that | D．in which |
This is one of the means ____t he electic energy is conducted from one place to another.
| A．by which | B．by that | C．through which | D．through that |
The buses, ____were already full, were surrounded by an angry crowd.
| A．most of them | B．most of which | C．which most | D．that most |