设的内角A、B、C的对边分别是a、b、c，若 ， 则的形状是（   ）

We did have a quarrel about money last night, but now we have already ______.

互为同位素的微粒是（   ）

下列各组物质中，互为同位素的一组是（   ）

补写出下列句子空缺部分

阅读下列短文，从每题所给的四个选项(A、B、C和D)中选出最佳选项。

    If cars had wings，they could fly and that just might happen，beginning in 2011.The company Terrafugia，based in Woburn，Massachusetts，says it plans to deliver its car­plane，the Transition，to customers by the end of 2011.

    “It's the next ‘wow' vehicle，” said Terrafugia vice president Richard Gersh.“Anybody can buy a Ferrari，but as we say，Ferraris don't fly.”

    The car­plane has wings that unfold for flying－a process the company says takes one minute－and fold back up for driving. A runway is still required to take off and land.

    The Transition is being marketed more as a plane that drives than a car that flies，although it is both. The company has been working with FAA to meet aircraft regulations，and with the National Highway Traffic Safety Administration to meet vehicle safety regulations.

    The company is aiming to sell the Transition to private pilots as a more convenient and cheaper way to fly. They say it saves you the trouble from trying to find another mode of transportation to get to and from airports：You drive the car to the airport and then you're good to go. When you land，you fold up the wings and hit the road. There are no expensive parking fees because you don't have to store it at an airport－you park it in the garage at home.

    The car­plane is designed to fly primarily under 10,000 feet. It has a maximum takeoff weight of 1,430 pounds，including fuel and passengers. Terrafugia says the Transition reduces the potential for an accident by allowing pilots to drive under the bad weather instead of flying into marginal(临界的) conditions.

    The Transition's price tag：$194,000.But there may be additional charges for options like a radio，a transponder or a GPS. Another option is a full­plane parachute.

    “If you get into a very awful situation，it is the necessary safety option，” Gersh said.

    So far，the company has more than 70 orders with deposits. “We're working very closely with them，but there are still some remaining steps，” Brown said.

— Excuse me, Dad, but I'm going to the club to meet my friends in the football team.

— Ok. _____.

任务型阅读

    From time to time, we all get a bit down. Maybe we are feeling bad because we're not doing well with our goals. There are many reasons for feeling down, but I'm not able to discuss all of them.

    Make a list. Sometimes we are sad simply because we are troubled by all the things we have to do. Make a list of the most pressing things you have to do. Thus you're getting things under control. You can see, right in front of you, what you need to do, and that can pick up your mood.

    You've made a list, and you still feel puzzled? Well, get started on the first thing you need to do. Once you get into action, you'll feel better. And once you start doing something, you will feel much better than lying around feeling sorry for yourself.

    I like Brown Eyed Girl, the Kinks, the Ramones, or an upbeat Beatles tune. You might have your own brand of feel-good music. Whatever it is, let yourself move to the beat. It may just be what the doctor ordered.

    Talk about it. Get a best friend, family member or coworker you can talk to. It can also help you work out the reasons you're feeling down.

A. Take action. B. Play some lively music. C. Get out of the house and do something. D. Getting things off your chest makes a big difference. E. Start simply by picking up a piece of paper and a pen. F. Do whatever you need to do to feel good about yourself. G. What I can talk about are some things that have worked for me.

△ABC中，角A，B，C所对的边分别为a，b，c，若c＜bcosA，则△ABC为（   ）

下列各组物质中，互为同位素的是(     )  

It took him many years to recover the death of his father.

We'd love to accept your (invite) to visit you sometime.

室温下，将100mL某盐酸和硫酸的混合溶液分成两等分．一份加入过量BaCl₂溶液，充分反应后得沉淀2.33g；另一份加入50mL 1.0 mol•L^﹣1NaOH溶液，充分反应后溶液的pH=13（溶液的体积为100mL）．试计算：

（1）每份溶液中所含H₂SO₄的物质的量　 　mol    

（2）原混合溶液中盐酸的物质的量浓度为　 　 mol•L^﹣1 ．

已知A（ 2，1 ），B（ 3，2 ），C（﹣1，5 ），则△ABC的形状是（   ）

有两种金属的合金13 g，与足量稀硫酸反应后，在标准状况下产生气体11.2 L，则组成该合金的金属不可能是（   ）

改错题

These days we have spent as much time as we could prepare international flower exhibition.

假定英语课上老师要求同桌之间交换修改作文，请你修改你同桌写的以下作文。文中共有10处语言错误，每句中最多有两处。每处错误仅涉及一个单词的增加、删除或修改。

增加: 在缺词处加一个漏字符号(∧)，并在其下面写出该加的词。

删除: 把多余的词用斜线(\)划掉。

修改: 在错的词下划一横线，并在该词下面写出修改后的词。

注意: 1）每处错误及其修改均仅限一词;

2）只允许修改10处，多者(从第11处起)不计分。

    Dr Yuan Longping is a agricultural pioneer in China. He graduates from Southwest Agricultural College in 1953. Since then he has devoted himself to find ways to grow more rice. The rice farmers are now producing twice as larger harvests as before by using the kind of rice he bred. But he is not satisfied with his work. Although now he leads a rich life, but he still insists on his work to develop his rice. I think his work is real important to the world. Because of he hard work, the production of food been improved. Thanks for Yuan Longping's research, we have more tools in the battle to rid the world of hungry.

阅读下面的材料，根据要求作文。

在生活中，我们有时是去敲门，有时是被敲门，敲门是再寻常不过的动作。但这个寻常的小动作中却往往蕴含着丰富的信息。实际上，敲门是人生必须面临的课题，多少人在一扇扇有形或无形的门面前，停住了脚步，缩回了举起的手，被永远隔在成功的大门之外。

请以“敲门”为标题，写一篇不少于800字的记叙文。

要求：①立意自定；

②角度自选；

③不要脱离材料内容及含义的范围作文；

④不要套作，不得抄袭。

单句改错

There are certain jobs that are stressful,  the ones in business or the police.