—Sorry. I went out just now.
A:took away
B:took up
C:took off
D:took out
①﹣3是函数y=f(x)的极值点;
②﹣1是函数y=f(x)的最小值点;
③y=f(x)在x=0处切线的斜率小于零;
④y=f(x)在区间(﹣3,1)上单调递增.
则正确命题的序号是____.
____是 ____的 ____倍.
列式: ____÷ ____= ____