--Why are your eyes so red? You _______ have slept well last night.

A．can't

B．mustn't

C．needn't

D．won't---Yeah, I stayed up late writing a report.

已知程序段：

s=0

For i=1 To 10 Step 2

s=s+1

i=i*2

Next i

当循环结束后，变量i的值为______，变量s的值为______。

A．10，4

B．11，3

C．22，3

D．16，4