从所给的四个选项中，选择最合适的一个填入问号处，使之呈现一定的规律性（）
A．
B．
C．
D．
参考答案：C
students with their teachers a good weekend. [ ]
A. Many a; has
B. A large number of; had
C. A large amount of; had
D. A lot of; has had
延迟裂纹属于（）裂纹。
A.冷
B.热
C.再热
