题干

一物体从高H处自由下落,当速度为到达地面时速度的一半时,它下落的高度是:

A:H/2;

B:H/4;

C:3H/4;

D:

上一题 下一题 0.0难度 选择题 更新时间:2016-07-26 10:45:46

答案(点此获取答案解析)

B

同类题1

阅读下面短文,用括号内所给动词的适当形式填空,必要时可加助动词或情态动词.

    One day,I took my daughter to the park.As soon as we got there,my daughter ____(run) to the swing (秋千)and asked for a push.When I was helping my daughter,I noticed another girl trying to make her own swing ____(go) high by herself.Her old grandmother was sitting on the chair nearby and smiling at us.Gradually,my daughter ____(push) higher and higher by me.

    Then I walked towards the little girl.I asked if I ____(give) a big push to her.She smiled and said “Yes”. For the next hour,I pushed the swings,and played with my daughter and the little girl. When we went home,I ____(be) tired but very happy.

    One day two years later,after a day's work,I went to pick up my daughter before going home.

    While I ____(wait) outside the school gate,a little girl smiled sweetly at me and gave me a big hug.As I watched her ____(run) away,I realized that she was the girl whom I gave a big push in the park.

    So far,I ____(not forget) her sweet smile and the warm hug that she gave me.

    In fact,if we give love to others,love ____(find) its way back to us.It may travel from heart to heart or it may blossom (开花)in the heart.The love we share,the kindness we ____(give),and the happiness we create will come back to us with a pleasant surprise.

同类题2

五百年来,在人类现代化进程的大舞台上,相继出现了九个世界性大国,他们的强国历程为世界关注。阅读下列材料。

材料一: 1500年以前,人类基本上生活在彼此隔绝的地区中。……直到1500年前后,各种族集团之间才第一次有了直接的交往。……因此,1500年是人类历史上的一个重要转折点。                      ——(美)斯塔夫里阿诺斯《全球通史》

材料二:美国黑船压境的傲慢和强势,凸现出幕府的软弱无能,来自外部的压力终于演变为内部变革的动力。最终,武士们以王政复古的名义推翻了幕府,扶持刚刚登基的明治天皇,建立起合法的新政府。14岁的明治天皇成为日本国的最高领袖。年轻的天皇所要领导的,是一个内忧外患、危机四伏的日本。                                              ——《大国崛起))解说词

材料三:此时的英国,正在孕育人类历史上一种崭新的生产方式,后世称之为“工业革命”。持续的海外扩张和殖民贸易,带动了对商品的需求;科学意识和市场意识,提高了英国人普遍的认识水准。在各种合力下,英国成为世界上第一个工业化国家,开创了影响深远的自由主义经济模式,并建立起一个夸全球的‘旧不落帝国”,在18世纪中期到19世纪中期,引领着世界的发展。

材料四:电视专题片《大国的崛起》有这样一段解说词:“在美国首都华盛顿,林肯纪念堂和华盛顿纪念碑遥遥相望。有人说,是华盛顿创立了美国,是林肯拯救了美国。”

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