下列有关化学键与晶体结构的说法中，正确的是
| A．含有阴离子的化合物中一定含有阳离子 | B．非金属元素组成的化合物一定是共价化合物 |
| C．干冰升华时，分子内共价键会发生断裂 | D．两种元素组成的分子中一定只有极性键 |
If you leave the club, you will not be_____back in .
| A．received | B．admitted | C．turned | D．moved |
What I need is_____ book that contains ______ABC of oil painting.
| A．a; 不填 | B．the; 不填 | C．the; an | D．a ; the |
Jenny nearly missed the flight______ doing too much shopping.
| A．as a result of | B．on top of | C．in front of | D．in need of |
The CDs are on sale! Buy one and you get ______ completely free. 
| A． | other | B． | others | C． | one | D． | ones |
I’m sure that your letter will get______ attention. They know you’re waiting for the reply. 
| A．continued | B．immediate | C．careful | D．general |