与物流相关的客户服务的提供主体有（） A.加工企业 B.制造企业 C.流通企业物流部

某种超导磁悬浮列车是利用超导体的抗磁作用使列车车体向上浮起，同时通过周期性地变换磁极方向而获得推进动力。其推进原理可以简化为如图所示的模型：在水平面上相距6的两根平行直导轨间，有竖直方向等距离分布的匀强磁场B₁和B₂，且B₁=B₂=B，每个磁场的长都是a，相间排列，所有这些磁场都以速度v向右匀速运动，这时跨在两导轨间的长为a宽为b的金属框MNQP（悬浮在导轨正上方）在磁场力的作用下也将会向右运动。设金属框的总电阻为R，运动中所受到的阻力恒为f，求：

(1)列车在运动过程中金属框产生的最大电流；

(2)列车能达到的最大速度；

(3)简述要使列车停下可采取哪些可行措施？

生病：医药（）

A．空虚：信仰

B． 糊涂：明白

C． 雷雨：大风

D．难过：高兴

阅读理解。

     If you don't want people to know too much about you, then you had better keep your fridge contents

secret according to a British market research document released last week.

     Researchers peered (凝视) into the fridges of 400 people in Britain and compared the contents with the

owners' lifestyles. They claim to be able to classify the nation's people by fridge contents.

     They say those people can be divided into five categories: "nutrition nerds", "food faddies", "martyr

mums", "fast food fanatics" and "restaurant regulars".

     "Nutrition nerds" care much about what they put into their bodies. Their fridges are stocked with fruit,

vegetables and healthy meat. People in this category tend to be highly organized and usually work in law or

accountancy. The vast majority are single, but if they have a partner, that person will be similar.

     A fridge full of vitamins-enriched juices implies its owner works in media or fashion. They tend not to

eat the foods they buy. Known as the "food faddies", they just want to be seen as buying the latest important

things.

     A fridge filled with everything from steak to frozen fish suggests the "martyr mum". Her fridge tends to

be stocked with every kind of product, except what she herself would want. This fridge hints at difficulty

balancing family and work life.

     "Fast food fanatics" always buy mineral water for soda pop (汽水); the nearest they will get to fresh

fruit is tomato sauce. Their fridges hint at someone who works hard and plays hard, also, someone who is

not into long term planning.

     Finally, a fridge filled with nothing more than a bottle of white wine and some sparkling mineral water

implies an owner who is single, lives in a big city and enjoys the finer things in life. The fridge is empty

because this person regularly eats in restaurants.

1. We can know from the first two paragraphs that _____.

A. some researchers are fond of staring at other people's fridges

B. people don't want others to know about their secrets

C. the food you put in the fridge has something to do with your personality

D. there are mainly five kinds of lifestyles among British people

2. According to the passage, people who belong to "food faddies" _____.

A. don't care much about money when buying things

B. will try their best to stay healthy

C. often stay up late to finish their job

D. prefer to ask others about what to do next

3. What will those who often dine out put in the fridge?

A. All kinds of food they like.

B. Food rich in vitamins.

C. Fruit, vegetables and meat.

D. Only something to drink.

4. What might be the most suitable title for the text?

A. Keep your fridge a secret.

B. You are what's in your fridge.

C. What to put in the fridge?

D. Be careful about your fridge

2011年5月27日，第二届印度一非洲论坛峰会在非洲联盟总部所在地、埃塞俄比亚首都亚的斯亚贝巴召开，成为世界瞩目的焦点。作为金砖四国的印度，摆脱英国殖民统治获得独立的时间是[ ]

A．1945年

B．1946年

C．1947年

D．1949年

典型胆囊结石的超声表现为（）、（）、（）。