69. The Queen presented the prizes (亲自).
68. My (指示) are that I am not to let anyone in.
67. Success is (取决于) on how hard you work.
66. Each ticket (许可) two people to the party.
5. conclusion A. lose B. student C. suggestion D. pleasure
第二节 补全对话 (共5小题；每小题1分，满分5分)
根据对话内容，从对话后的选项中选出能填入空白处的最佳选项，并在答题卡上将该项涂黑。选项中有两项为多余选项。
-- Professor Smith, I have a record of my studies for last year?
-- Would you like to see it?
-- Yes, sir.
-- John, 61
-- Yes, sir. But I’d like to apply to admission to Cambridge University.
-- I see. 62
-- Yes, Mr. Smith. They think it’s a very good idea.
-- Well, your record here has been very good. 63
-- 64 Anyway, I’m going to apply. And I’d like to ask you to write a recommendation(推荐信) for me if it is not too much trouble.
-- 65
-- Thank you very much, Professor.
-- All right. Good luck to you.
A. I don’t think you’ll have much trouble.
B. Are you getting on well with your studies?
C. I hope not.
D. You are studying mathematics, aren’t you?
E. I’d like to talk with you about my studies for a minute, if I may.
F. Have you asked your parents for their advice?
G. Not at all. I’d be glad to.
第三节 单词拼写(10小题，每小题1分；满分10分)
根据下列句子及所给汉语注释，在答题卡上相应题号的横线上写出空缺处各单词的正确形式。(每空只写一词)
4. ocean A. other B. often C. only D. occur
3. breathe A. wealth B. although C. thin D. mathematics
2. treat A. season B. ahead C. ear D. break
1. fat A. nation B. natural C. hate D. ashamed
2．(1)近期媒体报道，叛逃到英国的俄罗斯前特工利特维年科在伦敦离奇身亡．英国警方调查认为，毒杀利特维年科的是超级毒药--放射性元素钋(Po)．Po的半衰期为138 d，经衰变生成稳定的铅(Pb)，那么经过276 d，100 g Po已衰变的质量为________g.
(2)一个氘核(H)和一个氚核(H)结合成一个氦核并放出一个中子时，质量亏损为Δm，已知阿伏加德罗常数为NA，真空中的光速为c，若1 mol氘和1 mol氚完全发生上述核反应，则在核反应中释放的能量为________．
A．NAΔmc2 B．2NAΔmc2 C.NAΔmc2 D．5NAΔmc2
(3)用速度为v0、质量为m1的He核轰击质量为m2的静止的7N核，发生核反应，最终产生两种新粒子A和B.其中A为8O核，质量为m3，速度为v3；B的质量为m4.
①计算粒子B的速度vB.
②粒子A的速度符合什么条件时，粒子B的速度方向与He核的运动方向相反．
解析：(1)根据半衰期的定义，经过276 d(两个半衰期),100 g Po已衰变的质量为+＝75 g.
(2)根据爱因斯坦的质能方程，一个氘核(H)和一个氚核(H)结合成一个氦核并放出一个中子释放的能量为Δmc2,1 mol氘和1 mol氚完全发生上述核反应，释放的能量为上述反应的NA倍，即NAΔmc2.
(3)①由动量守恒定律有：m1v0＝m3v3+m4vB，解得：vB＝.
②B的速度与He核的速度方向相反，即：m1v0－m3v3<0，解得：v3>.
答案：(1)75 (2)A (3)① ②v3>