镍镉（Ni—Cd）可充电电池在现代生活中有广泛应用，它的充放电反应按下式进行：（ ）。
Cd(OH)2+2Ni(OH)2 Cd+2NiO(OH)+2H2O由此可知，该电池放电时的负极材料是
| A．Cd | B．Ni(OH)2 | C．Cd(OH)2 | D．NiO(OH) |
I can’t leave. She told me that I ______ stay here until she comes back.
| A．can | B．must | C．will | D．may |
—— Do you mind my opening the window? It’s a bit hot in here.
—— ______ , as a matter of fact
| A．Go ahead | B．Yes, my pleasure |
C．Yes, I do | D．Come on |
It’s high time you had your hair cut ; it’s getting _______ . 
| A．too much long | B．much too long |
C．long too much | D．too long much |
My friend showed me round the town, ______ was very kind of him. 
| A．which | B．that | C．where | D．it |
They use computers to keep the traffic _______ smoothly.
| A．being run | B．run | C．to run | D．running |