超声诊断成熟卵泡的标准是:①卵泡表面无卵巢组织覆盖②卵泡长径≥20mm③卵泡张力高,壁薄而光滑④子宫直肠窝少量积液
A.①
B.①②
C.①②③
D.①②③④
E.①③
参考答案:C
2100是4的倍数,所以2100年是闰年.______.(判断对错)
---He seems to be lost in thought. Why?
---Because the film _____ his memories of his childhood. [ ]
A.calls up
B.picks up
C.brings up
D.takes up