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

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答案(点此获取答案解析)

C

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    Terrible disasters in the last 50 or 100 years have become increasingly common. Over the last 30 years, the number of weather-related disasters has increased quickly, and the disasters have also affected more people and caused more economic loss. However, much of this could be avoided through disaster risk reduction(DRR降低灾难风险).

    A meeting, held in Sendai, Japan last month, opened one day after Cyclone Pam(飓风Pam)hit Vanuatu, which struck the islands with winds of up to 340km/h and destroyed the island nation. The speech by the President of Vanuatu was given shortly after that. He begged the international community for support and stronger commitment (承诺)to helping them manage climate and disaster risks. In the face of disasters, it is always the developing countries that suffer most. Damage in these countries is often worse and unluckily, there is limited money and technique to prevent these disasters.

    In fact, we have seen Asian countries-especially those that have suffered a lot in disasters can't pay the price. Great loss Asia has suffered comes to a total of almost $ 53 billon yearly over the past 20 years.

    At the same time, studies have shown once again that proper prevention saves lives and damage. With this in mind, people at the Sendai meeting were able to come up with new agreements that effective ways of disaster risk reduction will be carried out in the coming years for those who easily get damaged in disasters.