局站交流基础电源由（）和（）组成。
A.AC
B.市电
C.发电机组
D.UPS
参考答案：B, C
—You are always full of _______. Can you tell me the secret?
—Taking plenty of exercise every day. [ ]
A. power
B. strength
C. force
D. energy
笋干丝(塑料袋装；净重250g)
