腹部叩诊移动性浊音阳性,腹水量至少为()。
A.150ml
B.500ml
C.800ml
D.1000ml
E.1200ml
参考答案:A
In addition to cultural differences, overseas students have to overcome linguistic ______ as soon as possible.
A.hindrance
B.impediment
C.barriers
D.hurdles
试述骶丛的组成和位置。