下列设备中属于输入设备的是（）。
A.耳机
B.鼠标
C.扫描仪
D.打印机
E.投影仪
参考答案：B, C
Please don't forget ______ the flowers to Mrs Wang. It's her birthday today.[ ]
A. send
B. sending
C. will send
D. to send
You ______ the experiment twice, not once.
A．should have carried out
B．shouldn't have carried out
C．haven't carried out
D．couldn't have carried out
