螺旋桨发动机上反向拉力是如何产生的()?
A.桨叶角转到负值
B.桨叶角为低桨叶角
C.螺旋桨转到顺桨位
D.桨叶角为高桨叶角
参考答案:A
The headmaster said they would have _______ library _______. [ ]
A. another, built
B. other, built
C. another, build
D. other, building
目前,我国国债包括记账式国债、凭证式国债和储蓄国债三类。 ( )