-_____ was your trip?
-It was very nice.[ ]
A. What
B. Where
C. How
D. When
答案:C
下列语句中:①m=x3-x2 ②T=T×I ③32=A ④A=A+2 ⑤a=b=4其中是赋值语句的个数为( )
A.5
B.4
C.3
D.2
均质圆环的质量为m,半径为R,圆环绕O轴的摆动规律为φ=ωt,ω为常数。图4-74所示瞬时圆环对转轴O的动量矩为()。
A.mR2ω
B.2mR2ω
C.3mR2ω
D.