宫外孕破裂的麻醉选择主要取决于（）
A.病人脊柱形态
B.病人身高
C.病人年龄
D.病人失血程度
E.病人体重
参考答案：D
两台离心泵串联会增加其出口压力和流量。（）
With barter, however, debtor nations can continue to import goods while, in effect, concealing export earnings from creditors. ( )
A．loaners
B．borrowers
C．owners
D．believers
