—Whenever you have difficulties, be sure to call me. —________________.
A:I have no trouble
B:I am sorry to hear that.
C:I will. Thank you very much.
D:I will think it over.
如图所示的电路中,电源电压不变,开关闭合后,若滑动变阻器的滑片P向右端移动,则 ( )
一种气态烷烃和一种气态烯烃组成的混合物共10g,混合气体的密度是相同状况下H2密度的12.5倍.该混合气体通过装有溴水的试剂瓶时,试剂瓶的质量增加了8.4g.该混合气体可能是( )
试证当n为正整数时,f(n)=32n+2﹣8n﹣9能被64整除.