—How long ____ you ____a fever?
—Ever since last night.
根据后面的since我们可以判断要用完成时。而get,catch等瞬间动词在完成时中不能与for,since引导的时间状语连用，答案是B.
—How long ____ you ____a fever?
—Ever since last night.
—The artist has got _____ much work to do that he hardly has time to help his wife with the housework.
—That’s true. Even on Sundays he is busy with his work.
—What do you think of these two books?
—_____ of them are interesting. And I’ve read them several times.
—My trousers are______ .
—I’ll buy you a new pair.
—Will you please show me how to operate the new machine?
—Sure. It’s a piece of cake. Now let me tell you _____ to do first.
—May I go out with you tomorrow?
—If your job ______by then.
已知O为坐标原点，直线l：y＝﹣1/2x＋2与x轴、y轴分别交于A、C两点，点B（4，2）关于直线l的对称点是点E，连接EC交x轴于点D．
（1）求证：AD＝CD；
（2）求经过B、C、D三点的抛物线的函数表达式；
（3）当x＞0时，抛物线上是否存在点P，使S△PBC＝5/3S△OAE？若存在，求点P的坐标；若不存在，说明理由．
The children ______ not to play with the fire.
With the help of the computer, information can ____every corner of the world swiftly.
如图，PM、PN是⊙O的切线，切点分别是A、B，过点O的直线CE∥PN，交⊙O于点C、D，交PM于点E，AD的延长线交PN于点F，若BC∥PM．
（1）求证：∠P＝45°；
（2）若CD＝6，求PF的长．
