— What made her so sad？
— _____ she failed in the examination.
| A．That | B．Because | C．As | D．Since |
His spare time is made full use_______ law.
| A．to study | B．study | C．of studying | D．of to study |
Mark needs to learn Chinese _______ his company is opening a branch in Beijing.
| A．unless | B．until | C．although | D．since |
sales of cars up by 30% last year, the traffic in Beijing has become increasingly terrible.
| A．With | B．Since | C．For | D．As |
It is recognized that the part ___ the UN plays in international relations is important.
| A．in which | B．where | C．that | D．of which |
Who would you rather ______ with the teacher about the problem?
| A．talking | B．talk | C．have talked | D．have talk |