机翼的上反角可以产生().
A.俯仰阻转力矩
B.横向操纵力矩
C.横向安定力矩
参考答案:C
采用扣锅煅法炮制的药材是()
A.白矾
B.石膏
C.牡蛎
D.自然铜
E.血余炭
—_____ hotday!
—So it is! 1 hate _____ bad weather[ ]
A. What a; such
B. How a; so
C. How;so
D. What;so