声像图显示肾囊肿要具备的标准是()。
A.无回声结构
B.包膜完整光滑
C.后方声加强
D.以上各项均是
参考答案:D
They didn’t turn up at the meeting yesterday. Otherwise, they _________ the report.
A.had listened to
B.would listen to
C.should listen to
D.would have listened to
单子叶植物根类中药维管束的主要类型是()
A.有限外韧型
B.周木型
C.辐射型
D.周韧型
E.无限外韧型