摘要:30. 某地在湖面上修建一座大桥.下图甲是使用吊车向湖底投放圆柱形石料的示意图.在整个投放过程中.石料以恒定速度v=0.1m/s下降.图乙是钢丝绳的拉力F随时间t变化的图像(从t=0时刻开始投放到石料刚好接触湖底).忽略水的摩擦阻力.g取10N/kg.求: (1) 完全浸没后.石料所受的浮力, (2) 圆柱形石料的密度, (3) 湖底受到水的压强. (解答要求:写出依据的主要公式或变形公式. 有数据代入.答案中必须明确写出数值和单位)

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阅读下列各小题,根据汉语提示,用句末括号内的英语单词完成句子,并将答案写在答题卡上的相应题号后。

1.If I had a pair of unseen wings, I ________ as freely as Spaceship Tiangong-1 in space. (fly)

如果我有一双隐形的翅膀,我就能像天宫一号一样在太空自由翱翔。

2.Once you have a “feel” for the language, you will _______ to understand the grammar. (find)

一旦你有了语感,你就会发现更容易理解语法。

3.It is only by going on adventure _______ knowing themselves. (succeed)

只有经历冒险,人们才能成功认识自我。

4._____ in London for over 50 years, Stephen had a great knowledge of the capital city. (live)

在伦敦生活了五十多年,史提芬对这座首都城市非常了解。

5.On her tenth birthday she received a box of chocolates with a card ____, saying “Happy birthday!” (attach)

在十岁生日时她收到了一盒巧克力,上面附有一张卡片,写着“生日快乐”。

6.Some experts demanded that _________________enough time for sleep. (give)

专家们要求应该给孩子们充足的睡眠时间。

7.On the top of the mountain _____, which attracts a lot of tourists every year. (stand )

山顶上有一座古庙,每年吸引了大量的游客。

8.No matter ______, he always finds time to walk his dog. (busy)

不管他多忙,他总是腾出时间遛狗。

9.It hurts most to love someone but not ______ in return. (love)

爱上某人却未被爱最让人痛苦。

10.The better prepared you are for the performance, ___ it will be for you to suffer from a stage fright. (possible)

为表演准备得越充分,你怯场的可能就会越小。

 

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