对砌筑用水泥砂浆和强度等级不小于M5的水泥混合砂浆，砂浆用砂的含泥量不应超过（）。
A、3%
B、4%
C、5%
D、6%
参考答案：C
无论何种情况，委托人在委托有效期内有权变更或撤销原来的委托指令。( )
The policeman told me that I had passed the driving test and never in my life _______ so happy and excited.
A．I felt
B．did I feel
C．I had felt
D．had I felt
