活性高的催化剂选择性就一定好。
参考答案:错
解析:活性高的催化剂选择性不一定好。
软件调试的目的是 ______。
A.发现错误
B.改正错误
C.改善软件的性能
D.挖掘软件的潜能
Did you know _____ at the bus stop? Maybe their teacher. [ ]
A. who are they waiting for
B. whom they are waiting for
C. whom they were waiting fot