驾驶人一边驾车，一边打手持电话是违法行为。
参考答案：对
With all the things she needed _____, she went home happily.[ ]
A. to buy
B. to be bought
C. buying
D. bought
设f(0)=0，且
存在，则
等于( )．
A．f'(
B．f'(0)
C．f(0)
D．
存在，则
等于( )．