若超过规定的特性值要求,将会直接影响产品安全性或造成产品整机功能丧失的质量特性是属于()
A、关键质量特性
B、重要质量特性
C、一般质量特性
D、次要质量特性
参考答案:A
用所给单词的适当形式填空
1. The people in the store were ______ (crowd).
2. Thank you for ______ (give) me so much help.
3. I ______ (go) to the beaches last week and the beaches _____ (be) beautiful.
4. They _____ (enjoy) _____ (swim) in the pool last Sunday.
5. We didn't go _____ (shop)because it was very _____ (rain).
质量为m的飞机,以速率v在水平面内做半径为R的匀速圆周运动,空气对飞机的作用力的大小为( )
A.mv2/R
B.m
C.mg
D.m