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。
From the dates _________ on the gold coin, we decided that it was made five hundred years ago.
A．marking
B．marked
C．to be marked
D．having been marked
体内津液已伤，多见（）
A．燥苔
B．润苔
C．腻苔
D．滑苔
E．糙苔
