—Next Wednesday.
A:when they will leave
B:when will they leave
C:when they leave
D:when do they leave
一根彩带长15分米,小红扎花用去其中的 25 ,小红用了多少分米彩带?(先涂色表示出小红用去的部分,再列式算一算。)
已知f′(x)是函数f(x)的导函数,将y=f(x)和y=f′(x)的图象画在同一个直角坐标系中,不可能正确的是( )