题干

如图所示为一种常用核桃夹,用大小相同的力垂直作用在B点比A点更易夹碎核桃,这说明力的作用效果与(   )

A:力的大小有关

B:力的方向有关

C:力的作用点有关

D:受力面积有关

上一题 下一题 0.0难度 选择题 更新时间:2018-05-02 10:01:26

答案(点此获取答案解析)

C

同类题3

阅读理解

    There are many different voices on charity donations recently. Chen TianQiao, one of the Chinese billionaires, gave away $115 million to the California Institute of Technology (Caltech) to help promote brain research. Chen has been interested in the brain research, believing it can advance the industries of artificial intelligence and virtual reality. However, this huge donation has caused heated discussion among Chinese scholars and internet users.

    Many criticized him for giving money to a foreign university rather than domestic institutes for brain research, which are developing fast and are catching up with the US in just a few years. RaoYi, a biologist at Peking University, even said the donation was a typical mistake.

    Others, however, support his choice. They believe Caltech is a more reasonable choice compared with Chinese research Institutes. Caltech has a long history and has taken a leading position in biology, and therefore it produces more efficient results. What's more, the results of the research will benefit not only the Americans, but also the rest of the world.

    A similar controversial(有争议的)case started two years ago when Pan ShiYi, chairman of SOHO China, donated $15 million to Harvard University to help disadvantaged Chinese Students.

    Many believe that China is still far behind in management and use of donated money, and that as a result, Chinese donators are looking abroad. In comparison, Western countries like the US, which have a long history of donating money, have well-developed systems that use money efficiently. They can also provide full access for donors who want to track the use of the money. To get more donations, Chinese universities should be braver and more honest. They need self-reflection rather than envy.