－ I need to write an ad to rent out our place now.

－______? Michael is looking for a place.

A．Why not

B．What for

C．Why bother

D．So what

中性环境下，灭菌温度如何适度变化以及时间如何适度变化

A．提高……提高
B．降低……提高
C．提高……降低
D．降低……降低
E．不需改变