氯化钠是典型的离子晶体，下列有关氯化钠晶体结构的有关叙述错误的是（ ）
| A．钠离子与氯离子之间通过静电吸引结合在一起 |
| B．与某个钠离子最接近的钠离子有12个 |
| C．某个钠离子周围的氯离子围成的空间结构为正八面体 |
| D．晶体中钠离子的半径比氯离子的半径小 |
It is often ______ that human beings are naturally equipped to speak.
| A．said | B．to say | C．saying | D．being said |
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 |