函数f (x)=cosx-sinx(x∈[-π,0])的单调递增区间为_____________
-Is there any possibility_________ you could pick me up at the airport?
-No problem. [ ]
A. when
B.that
C.whether
D.what
在汇款特殊业务中收费为二元的特殊业务为()。
A.退汇
B.挂失取款通知单
C.挂失密码
D.网银