回归测试是 ______ 维护中最常用的方法。
参考答案:校正性
(2013·安徽高考)It ________ be the vocabulary that caused you the problem in the exercise because you know a lot of words.
A.may
B.couldn't
C.should
D.needn't
There are many tall buildings on _________ sides of the street. [ ]
A. each
B. every
C. both
D. either