面积较大，平面精度较高的基准平面定位选用（）作为定位元件。
A.支承钉
B.可调支承
C.支承板
D.自位支撑
参考答案：C
We had no one _____us, for we could deal with the case all by ourselves.
A．help
B．to help
C．helped
D．helps
痰湿型不孕症的首选方是( )
A．二陈汤B．开郁种玉汤C．乌药汤D．苍附导痰汤E．启宫丸
