—I think you are right. We should talk with our parents or they may feel sad.
A:different from
B:surprised at
C:the same as
现代社会要求每个人树立终身学习的观念。下列古语能体现这种观念的是( )
若x-1+x+y=0,则xy的值为( )
如图是自行车传动机构的示意图,其中Ⅰ是半径为R1的大链轮,Ⅱ是半径为R2的小飞轮,Ⅲ是半径为R3的后轮,假设脚踏板的转速为n(单位:r/s),则自行车后轮边缘的线速度为( )