手机进行国际漫游时，必须先开通什么业务？（）
A.国际直拨
B.国际漫游
C.国际长途
参考答案：A, B
公安机关是对违法犯罪行为施加影响最普遍、最直接、最及时的力量。 ( )
_______________, we don’t have much spare time at the moment．
A．relaxing as doing sport is
B．As doing sport is relaxing
C．relaxed as doing sport is
D．As doing sport is relaxed
