24. The reason ______ he is absent from class is _______ he has caught a bad cold.
| A．why; because | B．that; what | C．for which；because | D．why; that |
Scientists say it may be five or ten years _______ it is possible to test this medicine on human patients.
| A．after | B．before | C．since | D．when |
I send you 100 dollars today, the rest _______ in a year.
| A．follows | B．followed | C．to follow | D．being followed |
Taking a plane is the quickest _______ to get to Tibet.
| A．mode | B．manner | C．means | D．method |
Though he is a(n) _______ worker, he works very hard.
| A．ordinary | B．common | C．usual | D．general |
_______ two exams to worry about, I have to work really hard this weekend.
| A．With | B．Besides | C．As for | D．Because of |