3. After his journey from abroad, Richard Jones returned home, 　　　　.

　 A exhausting　　 B exhausted　 C being exhausted　 D having exhausted

2. It’s very dangerous to be ____ to the SARS virus without any protection.

A disclosed　 B uncover　 C affected　 D exposed

1. -I enjoyed the food very much.

-I’m glad you like it. Please drop in any time you like.

-________

A. Is it all right?　　　　　　　　 B. I'm afraid I won't be free.

C. Yes, I will.　　　　　　　　　 D. That's great.

3.记“两球恰好颜色不同”为事件C则P(C)=

2.记“从中摸出一个球，放回后再摸出一个球，两球同时是黑球”为事件B则P(B)=

22.　 解：1. 记“从中一次摸出两个球，两球恰好颜色不同”为事件A则P(A)=

21.解：因为该点在圆外设直线斜率为K则方程为y-4=k(x-2)即kx-y+4-2k=0所以解得K＝所以直线方程为：或

20.1解：记“点数之和为8”为事件A则P(A)=.

2记“点数之和大于10”为事件B则P(B)=

19.解：设所求圆的方程为：(x+3)²+y²－13+(x²+(y+3)²－37)＝0

因为圆心在x-y-4=0上，所以＝－7所以圆方程是：

3.　 记“所选3人至少有1名女生”为事件C则其对立事件为A事件则P(C)=