在手电筒电路中，提供电能的是（ ）
A．灯泡
B．电池
C．导线
D．开关
在手电筒中，电源是电池，用电器是灯泡，所以提供电能的装置是电池．
故选B．
Generally, a farmer has more difficulty than a college graduate. [ ]
A. to earning livings
B. to ern his living
C. earning livings
D. earning his living
1.5-2岁婴幼儿良好大小便习惯的训练时间和方法。
