下列运算：①a3+a3=a6；②（﹣a3）2=a6；③（﹣1）0=1；④（a+b

如图所示，放在倾角α=30°的光滑斜面上的凹槽，长L=3.000m，质量M=0.16kg,凹槽两端用挡板封住。斜面底端固定一块与斜面垂直的挡板。凹槽的下端离挡板的距离L₀=1.000m，开始时凹槽是固定的，槽内放置一块质量m=0.16kg的小铁块（视为质点）。当小铁块从凹槽上端静止释放，并以加速度沿凹槽向下运动，经△t=0.100s后再释放凹槽。设凹槽和小铁块与挡板碰撞后均以原速返回，空气阻力不计，试求：（结果取三位有效数字）

（1）凹槽与挡板第一次碰撞前,铁块对凹槽做的功

（2）从凹槽释放到第二次与挡板碰撞瞬间，凹槽运动的路程

（3）从释放铁块到凹槽与铁块都静止时，铁块相对于凹槽运动的路程。

翻译下列句子，每个空格填一词。

1．昆明的大部分时间是很温暖的。

     It is                       of the time in Kunming.

2．你想参加歌唱比赛吗？是的，我很愿意。  

     Would you like                                  in the singing contest?  Yes,           love to.

3．南希来自法国，她会讲法语，她打算在今天下午去参观中国历史博物馆。    

     Nancy is from           . She can speak              . She's           to visit the history museum in China                

     aftemoon.

女性，32岁，因急性失血需要输血，当输入红细胞悬液约200ml时，突然畏寒，发热，呕吐一次，尿呈酱油样，血压75／45mmHg

紧急化验结果符合该病情的是（）

A.间接胆红素升高明显

B.直接和间接胆红素同时升高明显

C.尿中查见大量含铁血黄素

D.尿蛋白阳性、隐血阳性

E.尿中大量红细胞

以下是粪便无害化处理必须达到的基本要求，其中错误的是

A．杀灭全部血吸虫卵和钩虫卵，蛔虫卵减少95％

B．大肠菌群值应大于10^-4～10^-3g以上

C．防止苍蝇孳生和繁殖

D．避免污染居民区的环境

E．肥效可以不予考虑

Real policemen, both Britain and the United States hardly recognize any resemblance between their lives and what they see on TV—if they ever get home in time. There are similarities, of course, but the cops don’t think much of them.

The first difference is that a policeman’s real life revolves round the law. Most of his training is in criminal law. He has to know exactly what actions are crimes and what evidence can be used to prove them in court. He has to know nearly as much law as a professional lawyer, and what is more, he has to apply it on his feet, in the dark and rain, running down an alley after someone he has to talk to.

Little of his time is spent in chatting to scantily clad ladies or in dramatic confrontations with desperate criminal. He will spend most of his working life typing millions of words on thousands of forms about hundreds of sad, unimportant people who are guilty—or not—of stupid, petty crimes.

Most television crime drama is about finding the criminal; as soon as he’s arrested, the story is over. In real life, finding criminals is seldom much of a problem. Except in very serious cases like murders and terrorist attacks—where failure to produce results reflects on the standing of the police—little effort is spent on searching. The police have an elaborate machinery which eventually shows up most wanted men.

Having made an arrest, a detective really starts to work. He has to prove his case in court and to do that he often has to gather a lot of different evidence. Much of this has to be given by people who don’t want to get involved in a court case. So as well as being overworked, a detective has to be out at all hours of the day and night interviewing his witnesses and persuading them, usually against their own best interests, to help him.

A third big difference between the drama detective and the real one is the unpleasant moral twilight in which the real one lives. Detectives are subject to two opposing pressures: first as members of a police force they always have to behave with absolute legality, secondly, as expensive public servants they have to get results. They can hardly ever do both. Most of the time some of them have to break the rules in small ways.

If the detective has to deceive the world, the world often deceives him. Hardly anyone he meets tells him the truth. And this separation the detective feels between himself and the rest of the world is deepened by the simple mindedness—as he sees it—of citizens, social workers, doctors, law makers, and judges, who, instead of stamping out crime punish the criminals less severely in the hope that this will make them reform. The result, detectives feel, is that nine tenths of their work is reaching people who should have stayed behind bars. This makes them rather cynical.

It is essential for a policeman to be trained in criminal law（）

A. so that he can catch criminals in the streets

B. because many of the criminals he has to catch are dangerous

C. so that he can justify his arrests in court

D. because he has to know nearly as much about law as a professional lawyer