A:ON绳先被拉断
B:OM绳先被拉断
C:ON绳和OM绳同时被拉断
D:因无具体数据,故无法判断哪条绳先被拉断
Tony would like to be a teacher his father.
下列各式﹣3x,x+yx-y,xy-y3,﹣310,25+y,3x,x4xy中,分式的个数为( )
若函数fx=x-bx-a在区间-∞,4上是增函数,则有( )
听第三段对话,回答两个问题。