______ is know to us all, good friends ______ happiness and value to our life.
| A．It; add | B．As; add up | C．It; add up | D．As; add |
The British are not so familiar with different cultures and other ways of doing things, ________ is often the case in other countries.
| A．that | B．who |
| C．where | D．as |
________ some students are not aware of is ________ difficult life can be if they are not devoted to study.
| A．That; how | B．Which; what |
| C．What; what | D．What; how |
________ you are supposed to do ________ you don't like a thing is change it. Don't complain.
| A．That; why | B．What; when |
| C．What; where | D．That; how |
His younger sister may already be in high school now, in ________ case this picture book is too childish for her.
| A．that | B．which |
| C．whose | D．what |
It is by no means clear ________ the president can do something to end the strike.
| A．whether | B．which |
| C．that | D．what |