题干

下表中关于物质分类的正确组合是(   )

类别组合

酸性氧化物

碱性氧化物

酸

碱

盐

A

CO

CuO

H2SO4

NH3•H2O

Na2S

B

CO2

Na2O

HCl

NaOH

NaCl

C

SO2

Na2O2

CH3COOH

KOH

CaF2

D

NO2

CaO

HNO3

Cu(OH)2CO3

CaCO3

A:A  

B:B  

C:C

D:D

上一题 下一题 0.0难度 选择题 更新时间:2013-05-20 04:11:58

答案(点此获取答案解析)

B

同类题2

阅读理解

    Grey clouds move as low as smoke over the treetops at Lolo Pass. The ground is white. The day is June 10.It has been snowing for the past four days in the Bitterroot Mountains.Wayne Fairchild is getting worried about our trek over the Lolo Trail-95 miles from Lolo Montana to Weippe in Idaho, across the roughest country in the West. Lewis and Clark were nearly defeated 200 years ago by snowstorms on the Lolo. Today Fairchild is nervously checking the weather reports. He has agreed to take me across the toughest, middle section of the trail.

    When Lewis climbed on top of Lemhi Pass,140 miles south of Missoula, on Aug.12,1805,he was astonished by what was in front of him; "high mountain chains still to the West of us with their tops partially covered with snow."Nobody in what was then the US knew the Rocky Mountains existed, with peaks twice as high as anything in the Appalachians back East.

    Today their pathway through those mountains holds more attraction than any other ground over which they traveled, for its raw wilderness is an evidence to the character of two cultures:the explorers who braved its hardships and the Native Americans who prize and conserve the path as a sacred (神圣的)gift. It remains today the same condition as when Lewis and Clark walked it.

    The Lolo is passable only from July to mid-September. Our luck is holding with the weather, although the snow keeps getting deeper. As we climb to Indian Post Office, the highest point on the trail at 7,033 ft, we have covered 13 miles in soft snow, and we hardly have enough energy to make dinner. After a meal of chicken, I sit on a rock on top of the ridge .There is no light visible in any direction, not even another campfire. For four days we do not see another human being. We are occupied with the things that mix fear with joy. In our imagination we have finally caught up with Lewis and Clark.

同类题5

阅读材料:
材料一  2100多年前,中国汉代的张骞肩负和平友好使命,两次出使中亚,开启了中国同中亚各国友好交往的大门,开辟出一条横贯东西、连接欧亚的丝绸之路……为了使我们欧亚各国经济联系更加紧密、相互合作更加深入、发展空间更加广阔,我们可以用创新的合作模式,共同建设“丝绸之路经济带”。
——中华人民共和国主席***《弘扬人民友谊  共创美好未来——在纳扎尔巴耶夫大学的演讲》(2013年9月7日,阿斯塔纳)
材料二  15世纪初,中国明代著名航海家郑和七次远洋航海,每次到访印尼群岛,足迹遍及瓜哇,苏门答腊,加里曼丹等地,留下了两国人民友好交往的历史佳话,许多都传诵至今。 
——《***首次在印尼国会的演讲》
材料三  2013年9月和10月,中国******在出访中亚和东南亚国家期间,先后提出共建“丝绸之路经济带”和“21世纪海上丝绸之路”(简称“一带一路”)的重大倡议,得到国际社会高度关注。中国国务院总理***参加2013年中国—东盟博览会时强调,铺就面向东盟的海上丝绸之路,打造带动腹地发展的战略支点。加快“一带一路”建设,有利于促进沿线各国经济繁荣与区域经济合作,加强不同文明交流互鉴,促进世界和平发展,是一项造福世界各国人民的伟大事业。
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