After graduation from high school we will reach a point _________ we have to decide

which university to attend．

A．that

B．what

C．which

D．where

发生在钢材表面的裂纹、发裂、麻点等，大多数是由钢锭或连铸坯的（）造成的。

A.皮下气泡

B.化学成分不合格

C.偏析严重

D.重皮