1 . Now a majority of high school students in China fail to get a_____ sleep during the night so they find it difficult to stay energetic at school.

2 . Have you collected ________ (足够的) materials for your essay?

3 . Sugar is not an important element in bread, but flour is _______.

A．unique

B．essential

C．natural

D．adequate

4 . Had we made          preparations, we might have succeeded in the sports meet last week.

A．awkward	B．adequate
C．absurd	D．accurate