判断主动脉瓣狭窄严重程度的重要定量指标是
A.瓣口直径
B.瓣口面积
C.瓣口周长
D.跨瓣压差
E.B和D
参考答案：E
已知函数y=sin2x+2sinxcosx+3cos2x，x∈R，
（Ⅰ）求函数的最小正周期；
（Ⅱ）该函数的图象可由函数y=sinx（x∈R）的图象经过怎样的变换得到？
The key word in the sentence has been ______, so it doesn't make any sense to us.[ ]
A. picked up
B. left out
C. held up
D. made out
