题干

如图所示。处于匀强电场中的正三角形的边长为 ,电场的场强方向平行于三角形所在的平面。已知A、B、C三点的电势分别为 、 和20V。则该电场的场强大小为____V/m,方向为____。


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答案(点此获取答案解析)

,电场方向由B指向A

同类题2

刚刚结束的中共十九大报告中提出,要加强社会保障体系建设,全面建成覆盖全民、城乡统筹、权责清晰、保障适度、可持续的多层次社会保障体系。阅读下列关于社会保障的材料,回答问题:

材料一:在传统救灾救助体系中,历代政府十分重视对民办机构进行引导和管理。……从西周开始历代政府都设立了职责包括救济在内的政府管理机构和官员,……还设立了救灾效果绩效考核制度,对各级官员的救灾业绩进行考核,以认定其高下优劣,奖罚十分严朋。为了防范救灾过程中舞弊行为,制定了严格的防范措施。……十分注重灾前预防,官方的社会救灾机构更加注重灾后的救助。

一一摘自张寿《中国传统救灾体系当议》

材料二:本法案旨在增进公共福利,通过建立一个联邦的老年救济金制度,使一些州得以为老人、盲人、受抚养的和残疾儿童提供更为可靠的生活保障,为妇幼保健、公共卫生和失业补助法的实行做出妥善的安排;同时,旨在建立一个社会保险局……

一一摘编自(美国)《社会保险法》(1935年8月)

1980年,美国通货膨胀率接近10%,有25%的企业开工不足。里根上台后……要求政府、企业主和雇工三者共同承担社会保障基金来源,并鼓动私人企业投资保障行业,提倡由“福利国家”过渡为“福利社会”。

一一摘编自陈宝森《美国经济与政府政策-从罗斯福到里根》

材料三:战后英国陆续颁布了《家庭补助法》《国民工伤保险法》《国民救济法》《工资委员会法》等。……英国所有公民从出生那天起就有一张社会保障卡,从受抚养、上学、病残、就业和失业、丧偶或抚养子女、年老退休直到死亡都可以按规定获得相应的社会保障。……20世纪80年代后,缩小“福利国家”的规模。

一一摘编自黄安年《西欧和北欧国家的福利保障政策》

同类题5

任务型阅读

Chopsticks

    ⒈When chopsticks were invented?

    In fact, before the invention of chopsticks, Chinese ancestors actually used hands to eat, but how did they eat soup(汤菜)and porridge? ____ Chinese started to use chopsticks about 3,000 years ago in Shang Dynasty.

    ⒉Who invented chopsticks?

    The records of using chopsticks have been found in many written books but lack physical evidence. However many stories are about the invention of chopsticks. One says that Jiang Ziya, an ancient wise man, created chopsticks. ____ But there is no exact history record about the invention. We can only say that smart ancient Chinese invented chopsticks.

    ⒊How to use Chinese chopsticks.

    Using two slim sticks to pick up food is actually not difficult. You can do it if you practice it for some time, even if you are a foreigner. The key to managing chopsticks is keeping one chopstick in position while moving the other to pick up food. ____

    ⒋Chopsticks Manners

    Chopsticks are usually held in the right hand, and left-handed chopstick use is considered as improper in China. Playing with chopsticks is thought to be impolite. ____

    ⒌The philosophy of Chinese chopsticks

    Chinese philosopher Confucius advised people to use chopsticks instead of knives because the metal knives remind people of cold weapons, which mean killing and violence.

    ⒍A chopsticks-themed museum can be found in Shanghai

    If you are truly interested in chopsticks, you can pay a visit to the Shanghai Chopsticks Museum. The museum gathered more than 1,200 pairs of chopsticks from China, Korea, Japan and Thailand.____

A. Chopsticks were introduced to many other neighbor countries due to its lightness and convenience.

B. It is considered to be polite and thoughtful to pick up food for the elderly and children.

C. Bamboo chopsticks are most frequently used in Chinese daily life.

D. The oldest one was from the Tang Dynasty.

E. There also go around some other stories.

F. Remember to practice with patience.

G. They had to use sticks to eat them.