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5.右下圖為某物質(zhì)的分子模型示意圖,其中“   ”代表氫原子,“   ”代表氧原子。下列敘述正確的是                               (   )

    A. 此物質(zhì)屬于混合物

   B. 此物質(zhì)的化學(xué)式為HO

    C. 此物質(zhì)的一個(gè)分子由4個(gè)原子構(gòu)成

    D. 此物質(zhì)中氫元素與氧元素的質(zhì)量比是1:1

試題詳情

4.面值100元的新版人民幣的數(shù)字“100”采用光變色防偽油墨印刷,垂直看為綠色,傾斜看為藍(lán)色。在防偽油墨中含有MgF2,其中F元素的化合價(jià)為           (   )

    A. +1            B. +2            C. -1            D. -2

試題詳情

3.蒸饅頭時(shí),面堿(主要含Na2CO3)放多了會(huì)發(fā)黃。為除去過(guò)多的面堿,做饅頭時(shí)可加入適量    (   )

    A. 食醋           B. 食鹽           C. 黃酒           D. 白糖

試題詳情

2.下列物質(zhì)中屬于氧化物的是                        (   )

    A. 食鹽           B. 水             C. 空氣           D. 酒精

試題詳情

1.運(yùn)用2008年諾貝爾化學(xué)獎(jiǎng)的研究成果,可依據(jù)生物發(fā)光現(xiàn)象檢測(cè)超微量鈣的存在。這里的“鈣”是指                               (   )

    A. 分子           B. 原子           C. 元素           D. 單質(zhì)

試題詳情

25.You    much more easily in a foreign company,on condition that you have a good spoken command of English.

  A.will promote      B.promote        C.will get promoted   D.are promoted

  答案  C

試題詳情

24.-Have you seen Jack in his office?

  -Yes,he     the report on the market research since eight this morning.

  A.has preparing for                B.has been preparing

  C.prepared                    D.is going to prepare

  答案  B

試題詳情

23.-Which hotel are you in?

  -I    in a hotel.A friend I met on the train from the south    to put me up for a couple of

nights.

  A.haven’t stayed;has offered           B.am not staying;offered

  C.am not staying;is offering           D.do not stay;offers

  答案  B

試題詳情

22.Cold winters in Europe    almost entirely by 2080 because of the continuously global warming

  nowadays.

  A.are disappearing    B.have disappeared    C.will have disappeared D.will be disappeared

  答案  C

試題詳情

21.-Why are the Woods selling their belongings?

  -They    to another city.

  A.had moved        B.have moved       C.moved         D.are moving

  答案  D

試題詳情


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