After the Yushu earthquake, to make sure that rescue work could be carried out as smoothly as possible, Premier Wen Jiabao________ his visit to Brunei.

A．put away

B．put off

C．put up

D．put down

当把APU起动电门从ON位移到OFF位，等待多长时间APU会停车（）

A.40秒

B.120秒

C.60秒

D.100秒