2. The value of variables
Experiments must have the ability to be duplicatedbecause the'answers'the scientist comes up with (whetherit supports or refutes the original hypothesis) cannot becomepart of the knowledge base unless other scientists can performthe exact same experiment(s) and achieve the same result；otherwise， the experiment is useless.
3. Checking your stats
Of course these experiments would have to be performedmany times by many different runners to demonstrate anyvalid statistical significance. If an experiment is performedrepeatedly and the results are within a narrow margin， theresults are said to be significant when measured using thebranch of mathematics called statistics. If results are all overthe board， they are not that significant because one definiteconclusion cannot be drawn from the data.
4. Tracking the information
Once an experiment is designed properly， you can beginkeeping track of the information you gather through theexperiment.
5. Drawing conclusions
Draw conclusion about your hypothesis is true or untrue.
用科学的方法设计你的实验
科学家们怎么获得新知识的？当科学家们获取信息的时候，他们通常依靠科学的方法来进行。
1. 假定
科学家们做研究，会先有一个假说，关于某方面问题的假说，然后开始证明这个假说是正确的，或者反驳该假说。
2. 可复制
一项实验必须是可复制的，因为一名科学家通过实验得出的结论，除非另一名科学家通过同样的实验也得出同样的结论，否则不能成为基础知识的一部分，该实验也就毫无价值。
3. 检查统计数据
科学实验经过多人多次实验之后才能得出可靠的统计信息。
如果经过多次重复实验得出的结论，而且依据统计学，误差较小，这些结论才是有意义的。如果这些结论误差较大，那么这些结论意义不大，因为这些数据中没能得出一个确切的结论。
4. 跟踪信息
一旦进行相应的实验之后，你需要在实验过程中跟踪这些信息。
5. 下定结论
对假说的真实与否，作最后的结论。
Section 16 大学自助餐厅
At the Cafeteria in College
自助餐厅是大学的公众场所之一，注意保持环境卫生，节约食物避免浪费，还要注意举止文明，礼貌待人。
口头应急句
1. The food is really icky in the school cafeteria.
学校自助餐厅里的饭菜确实很差。
2. The cafeteria is on the ground floor.
自助餐厅在一楼。
3. Tell the man behind the counter what you want.
跟柜台后面的人说你想要什么。
4. Are those the food prices that are posted on the wall？
贴在墙上的是菜单吗？
5. When eating in a college cafeteria， you have a variety of foodfrom which to choose.
在自助餐厅吃饭，你可以有很多食物可以选择。
6. The cafeteria is not just a food joint but a place to relax， interact，rejuvenate and take a refuge from the daily hectic schedule.
自助餐厅不仅是用餐的地方，也是放松，交流，从忙碌中抽身，恢复身心的地方。
7. I want that fresh strawberry pie with whipped cream， thats myfavorite.
我要新鲜草莓馅饼加打起泡的奶油，那是我的最爱。
8. I am tired of the food in the school dinning room.
我厌倦了学校食堂的饭菜.
9. Let's join the line along the counter.
我们去柜台那排队吧。
10.The food price of the school canteen is not high.
学校食堂的饭菜价格不高。
11.Our cafeteria is open to the entire university community as wellas the general public.
我们自助餐厅向整个大学社区包括公众开放。
12.Our school canteen's meals are diverse.
我们学校食堂的饭菜品种繁多。
13.College students have the ******* to eat whatever they want，whenever they want， thanks to the convenience and wide varietyof college cafeterias.
大学自助餐厅用餐方便且饭菜品种多样，学生可自由随便吃。
14.How long will it take to reach the buffet
什么时候才排到柜台呢。
超经典情景对话链接
经典一
Emily： Aren't you hungry？
Sam： No， I am not. Not really.
Emily： Well， it's 11：30， and I am. The cafeteria is on the ground floor.
Sam： But it's expensive， isn't it？
Emily： No， it isn't.
Sam： How is the food？
Emily： It's not bad.
Sam： OK. Then， let's go to the cafeteria.
Emily： This way， please.
Sam： What's that？
Emily： That is stew. And I recommend baked potatoes to you.
Sam： What do you want to order？
Emily： I would like to order vegetable and soup.
Sam： I think I need a cup of coffee.
Emily： The coffee's at that counter over there.
Sam： Thank you. Let’s go and find a table.
艾美力：你饿了吗？
萨姆：不，没有。真不饿。
艾美力：哦，11点30分了，我肚子饿了。这里一楼有一个自助餐厅。
萨姆：那里餐很贵，是吗？
艾美力：不，不贵。
萨姆：饭菜质量怎样吗？
艾美力：还不错。
萨姆：好的，那我们去吃自助餐吧。
艾美力：请这边走。
萨姆：那是什么菜？
艾美力：那是炖肉。我给你推荐烤土豆。
萨姆：你想点什么？
艾美力：我想来点蔬菜和汤。
萨姆：我想要一杯咖啡。
艾美力：咖啡在那边的柜台。
萨姆：谢谢，我们去找个桌位坐下吧。
要点提示：
ground floor 第一层；一楼 a cup of 一杯
over there 在那边 be lost 迷失；不知所措
be crowded 拥挤的；塞满的 pick up 拾起；拿起
join in 加入
经典二
Ben： Oh， it's very crowded here.
Max： Yes. People like to eat in a cafeteria. It's cheap and quick.
Ben： What shall we do now I'm a bit lost.
Max： Just pick up a tray， put a knife， a fork， a spoon and a pa-per napkin onit， and then start down the line.
Ben： I see. Are those the food prices that are posted on the wall？
Max： Yes， you can choose whichever you want.
Ben： What a variety！ Barbecued chickens， fried fish， spaghetti…they allsound delicious.
Max： Yes. What are you going to have？
Ben： I'd like that fried fish.
Max： OK， let's join in the line along the counter.
本：噢，这里人真多。
马克斯：是的。人们喜欢到自助餐厅吃饭。便宜且快捷。
本：现在该怎么办？我不知所措。
马克斯：拿一个托盘，取刀叉、勺子、纸巾放在托盘里，然后去排队点菜。
本：明白了。贴在墙上的是菜单吗？
马克斯：是的，你可任意点自己喜欢的菜。
本：好多菜！烤鸡、炸鱼、意大利面…都是好吃的。
马克斯：是啊，你想点什么？
本：我想点炸鱼。
马克斯：好的，我们去排队吧。
词汇补给站
cafeteria [?k?f??t??ri?] n. 自助餐厅；食堂
recommend [?rek?'mend] v. 推荐；劝告
bake [be?k] v. 烤，烘；烘干
order ['?：d?(r)] n. 订单；下订单
counter ['ka?nt?(r)] v. 柜台
crowd [kra?d] n. 拥挤，聚集
fork [f?：k] n. 叉；餐叉
post [p??st] v. 张贴；贴出
variety [v?'ra??t?] adj. 品种，种类；多样化
barbecue ['bɑ：b?kju：] n. 烤肉
spaghetti [sp??geti] n. 意大利面条
点滴文化情
大学里的自助餐厅食物丰富多样，美味可口，是大学生每天都常光顾的地方，但是有的自助餐厅的经营有些问题，学生该如何反馈情况呢？这里是一位学生给学校自助餐厅写的建议书：
Dear sir or Madam，I have been a long time customer of the cafeteria sincemy first day in the College. I am writing to suggest some ideaswhich I think will greatly improve the service at the collegecafeteria.
First of all， I would like to thank all the staff of the cafeteriafor their service. I have to admit that staff is very friendly andthe cafeteria is spotlessly clean. Moreover， the meals are verydelicious and there are menus even for Muslim students andvegetarians.
Unfortunately， there are some shortfalls such as it is alwaysvery crowded and noisy as the space of the cafeteria is verycramped. Consequently， there are not enough tables for allthe students during lunchtime and therefore there are queueswaiting their turn to sit at the tables and have lunch. Forinstance， I had to wait in a queue for an hour frequently andwas late for my math lessons in the end.