排卵延迟的早孕,胚胎尚未出现,发生先兆流产,应注意与下面哪项鉴别()
①不全流产
②难免流产
③枯萎孕囊
④宫外孕
A.①
B.①②
C.①②③
D.①②③④
E.④
参考答案:B
Can you telephone me at to arrange a meeting? [ ]
A. convenience
B. service
C. request
D. comfort
测定肺换气效率较好的指标是
A.潮气量B.肺活量C.时间肺活量D.通气/血流比值E.肺扩散容量