分子式为C9H12的物质含有一个苯环且苯环上只有一个取代基，下列说话正确的是（ ）
A 该有机物不能发生加成反应，但能发生取代反应
B 该有机物不能是酸性高锰酸钾溶液退色，但能使溴水退色
C 该有机物分子中所有原子可能在同一平面上
D 该有机物属于苯的同系物，该类物质的通式为CnH2n-6（n≥6）
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 |