421.You should look ____ into the matter to get more information about it.
A.farther
B.far
C.farthest
D.further
422.We could hardly believe what she says because she is _____ changing her mind.
A.regularly
B.steadily
C.suddenly
D.constantly
421.答案是D;look further into the matter更深入地调查此事。
422.答案是D;regularly 定期地，有规律地；steadily 稳定地；suddenly 突然地;constantly 经常，不断
地。
