2x-x等于( )
A. x
B.-x
C. 3x
D.-3x
答案:A
根据同类项的定义及合并同类项的法则可求得2x-x=x.
故选A.
He said that we should protect the ancient civilization from _______.
A.losing
B.lost
C.being lost
D.to lose
商业银行服务价格分别实行政府指导价和()
A.协议约定价
B.行业议定价
C.市场平均价
D.市场调节价