How long will Wal-Mart take to become as big in China as it is in the America().

A. Half a decade.

B. A decade.

C. Two decades.

D. Several decades.

变压器在不通电的情况下可以用万用表的（）来初步判断其好坏，通过测量其直流电阻阻值判断其初次级线圈是否开路。