只有批准人员才能操作刹手。( )
A.Only approved personnel can operate the brakes. B.Only trained personnel must operate the brakes. C.Only approved people must operate the brakes.正确答案A
只有批准人员才能操作刹手。( )
A.Only approved personnel can operate the brakes. B.Only trained personnel must operate the brakes. C.Only approved people must operate the brakes.正确答案A
