氯化硼的熔点为－107℃，沸点为12.5℃，在其分子中键与键之间的夹角为120°，它能水解，有关叙述正确的是
| A．氯化硼分子呈正三角形，属非极性分子 | B．氯化硼中心原子采用 sp杂化 |
| C．氯化硼分子中含非极性键 | D．其分子空间结构类似NH3 |
在反应11P+15CuSO4+24H2O=5Cu3P+6H3PO4+15H2SO4中，1molCuSO4能氧化磷的物质的量是（ ）
| A．2/5 mol | B．1/5 mol | C．11/5 mol | D．1/3 mol |
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 |