采用提高风机转速来达到增容目的时，其风机所提高的转速一般不应超过（），否则易损坏风机。
参考答案：原转速的5%
The new chairperson of the Students' Union thought ______ necessary to invite Professor (教授) Smith to
give us a speech at the meeting. [ ]
A. that
B. this
C. him
D. it
动物的任何运动需要的能量都直接来自ATP。
