精液pH测定应在射精后多长时间内完成()
A．0.5h
B．1h
C．1.5h
D．2h
E．3h
参考答案：B
-_____ those your grandparents?
-No, _____.[ ]
A. Is; they are
B. Are; they are not
C. Is; it is
D. Are; it isn't
门静脉高压症患者脾切除术后，要定期监测血小板计数，目的是（）
A.防止血栓形成
B.观察有无出血倾向
C.观察有无再生障碍性贫血
D.观察有无急性白血病
E.观察有无缺铁性贫血
