胎儿血液含氧量最低的血管是（）
A.静脉导管
B.脐动脉
C.下腔静脉
D.肺静脉
E.主动脉
参考答案：B
When ________ why she could speak English so well, she just smiled and said nothing.
A．asking
B．to be asked
C．was asked
D．asked
个人耐用消费品贷款期限一般在( )年以内，最长为( )年(含)。
A．1,4 B．2,5C．1,3 D．2,4
