堆取料机液压系统的中的流量控制阀，只有油量充足时阀体才起作用。
参考答案：对
妊娠时尿糖阳性不一定是糖尿病。
“Have you seen the film?” he asked me. →He asked me _______.
A．had I seen the film
B．have I seen the film
C．if I have seen the film
D．whether I had seen the film
