根据使用的主要教学方法，课的类型分为( )。

单项选择题It was believed that things would get worse, but （）it is they are getting better.

A. before
B. after
C. because
D. as

单项选择题The president stood by a window inside the room,（）, looking over the square.

A. where I entered
B. into which I entered
C. which I entered
D. that I entered

单项选择题The students spent as much time getting trained as they （）studying.

A. disliked
B. were
C. had
D. did

单项选择题I have no one （）me, for I am a new comer here.

A. help                 
B, helping 
C. to help               
D. to have helped

单项选择题The engineers made two big plans for the dam, （）was never put in force.

A. one of them
B. which
C. one of which
D. every one of which