题干

如图所示,大小相同的摆球a和b的质量分别为m和3m,摆长相同,并排悬挂,平衡时两球刚好接触,现将摆球a向左边拉开一小角度后释放,若两球的碰撞是弹性的,下列判断中正确的是(   )

A:第一次碰撞后的瞬间,两球的速度大小不相等

B:第一次碰撞后的瞬间,两球的动量大小相等

C:第一次碰撞后,两球的最大摆角不相同

D:发生第二次碰撞时,两球在各自的平衡位置

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D

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    China's cancer researcher Zhu Chen, together with two French researchers Anne Dejean and Hugues de Thé, received Sjoberg Prize 2018 in Stockholm Concert Hall, Sweden on Friday.

    “We used wisdom from both Chinese and Western medicine and offered a cure to one of the most deadly cancers,” Chen told Xinhua, “I feel that Chinese medicine has potential to contribute more to human health. It struggles for benefiting all mankind. It's a language of peace, and of development and progress.” Chen recalled the cooperation with the two French researchers for over 30 years.

    This year's Sjoberg winners have developed a new and targeted treatment for a specific form of blood cancer called acute promyelocytic leukaemia (急性早幼粒白血病). It was once one of the deadliest forms of cancer, but it is now possible to cure nine out of ten patients who receive the new treatment. The winners have made this revolutionary development possible by methodically mapping the molecular mechanisms responsible for the disease.

    The Prize is awarded by the Royal Swedish Academy of Sciences and is funded (资助)by the Sjoberg Foundation. The foundation, with a donation of 2.5 billion US dollars, was founded in 2016, and serves to promote scientific research that focuses on cancer, health and the environment.

    The Prize is an annual international prize in cancer research awarded to individual researchers or research groups. The prize amounts to one million US dollars, of which 100,000US dollars is the prize sum and 900,000US dollars is funding for future research.