我国现有的经济体制是：[ ]
A．计划经济
B．社会主义市场经济
C．计划经济与市场经济结合
D．公有制经济
答案：B
It's hard to keep the house ________ with three kids. [ ]
A. cleaned
B. to clean
C. clean
D. have cleaned
ZNR突波吸收器
