题干

在密度知识应用交流会上,同学们想知道一个质量是14.4kg的课桌的体积.于是找来和课桌相同材质的木料作样本,测得其质量是14.4g,体积为20cm3,则样本的密度为____ g/cm3;课桌的体积为____ m3
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0.72,0.02

同类题2

阅读下面的作品,完成小题。

寂寞

梁实秋

    寂寞是一种清福。我在小小的书斋里,焚起一炉香,袅袅的一缕烟线笔直地上升,一直戳到顶棚,好像屋里的空气是绝对的静止,我的呼吸都没有搅动出一点波澜似的。我独自暗暗地望着那条烟线发怔。屋外庭院中的紫丁香还带着不少嫣红焦黄的叶子,枯叶乱枝的声响可以很清晰地听到,先是一小声清脆的折断声,然后是撞击着枝干的磕碰声,最后是落到空阶上的拍打声。这时节,我感到了寂寞。在这寂寞中我意识到了我自己的存在--片刻的孤立的存在。这种境界并不太易得,与环境有关,更与心境有关。寂寞不一定要到深山大泽里去寻求,只要内心清净,随便在市廛里,陋巷里,都可以感觉到一种空灵悠逸的境界,所谓“心远地自偏”是也。在这种境界中,我们可以在想象中翱翔,跳出尘世的渣滓,与古人同游。所以我说,寂寞是一种清福。

    在礼拜堂里我也有过同样的经验。在伟大庄严的教堂里,从彩色玻璃窗透进一股不很明亮的光线,沉重的琴声好像是把人的心都洗淘了一番似的,我感到了我自己的渺小。这渺小的感觉便是我意识到我自己存在的明证。因为平常连这一点点渺小之感都不会有的!

    我的朋友肖丽先生卜居在广济寺里,据他告诉我,在最近一个夜晚,月光皎洁,天空如洗,他独自踱出僧房,立在大雄宝殿的石阶上,翘首四望,月色是那样的晶明,蓊郁的树是那样的静止,寺院是那样的肃穆,他忽然顿有所悟,悟到永恒,悟到自我的渺小,悟到四大皆空的境界。我相信一个人常有这样的经验,他的胸襟自然豁达寥廓。

    但是寂寞的清福是不容易长久享受的。它只是一瞬间的存在。世界有太多的东西不时的提醒我们,提醒我们一件煞风景的事实:我们的两只脚是踏在地上的呀!一只苍蝇撞在玻璃窗上挣扎不出去,一声“老爷太太可怜可怜我这个瞎子吧”,都可以使我们从寂寞中间一头栽出去,栽到苦恼烦躁的漩涡里去。至于“催租吏”一类的东西打上门来,或是“石壕吏”之类的东西半夜捉人,其足以使人败兴生气,就更不待言了。这还是外界的感触,如果自己的内心先六根不净,随时都意马心猿,则虽处在最寂寞的境地里,他也是慌成一片,忙成一团,六神无主,暴跳如雷,他永远不得享受寂寞的清福。

    如此说来,所谓寂寞不即是一种唯心论,一种逃避现实的现象吗?也可以说是。一个高韬隐遁的人,在从前的社会里还可以存在,而且还颇受人敬重,在现在的社会里是绝对的不可能。现在似乎只有两种类型的人了,一是在现实的泥溷中打转的人,一是偶然也从泥溷中昂起头来喘口气的人。寂寞便是供人喘息的几口新空气。喘几口气之后还得耐心地低头钻进泥溷里去。所以我对于能够昂首物外的举动并不愿再多苛责。逃避现实,如果现实真能逃避,吾寤寐以求之!有过静坐经验的人该知道,最初努力把握着自己的心,叫它什么也不想,而是多么困难的事!那是强迫自己入于寂寞的手段,所谓参禅入定完全属于此类。我所赞美的寂寞,稍异于是。我所谓的寂寞,是随缘偶得,无需强求,一刹间的妙悟也不嫌短,失掉了也不必怅惘。但是我有一刻寂寞,我要好好地享受它。

(选自《梁实秋文集》)

同类题3

阅读理解

    Every day when Glen Oliver orders his morning coffee at the drive-through window of a local cafe, he insists on paying for the order of the person behind him. He also asks the restaurant workers to tell the customer to have a great day, in case they're not already having one.

    Oliver has never made a big deal out of his own generous actions until a letter was published by a news website in November. He found out that he had not just bought someone his breakfast —he had saved a life.

    According to the website, someone had written a letter stating that on July 18th, he was planning on committing suicide. The writer said that while he was at the drive-through window, he was planning on going home, writing a note and ending his life. When he went to pay for his coffee and muffin, however, the cashier told him that the man in the SUV in front of him had picked up the tab and told him to have a great day.

    “I wondered why someone would buy coffee for a stranger for no reason,” said the writer. “Why me? Why today? If I were a religious man, I would take this as a sign. This random act of kindness was directed at me on this day for a purpose.”

    When the writer arrived home, he couldn't hold back his tears and started to think about the simple good deed that had affected him so deeply. “I decided at that moment to change my plans for the day and do something nice for someone. I ended up helping a neighbor take groceries out of her car and into the house.”

    The writer says that in the months following that fateful event, he does at least one kind thing for others every day. “To the nice man in the SUV, thank you from the bottom of my heart. Please know your kind gesture has truly saved a life,” he said. “On July 18, 2017, I had the greatest day.”