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问题 选择题

下列各组中的物质化学式与俗名、名称均一致的是（  ）

A．CaO、滑石粉、氧化钙

B．NaOH、纯碱、氢氧化钠

C．Na2CO3、苏打、碳酸钠

D．CH3OH、酒精、乙醇

答案

答案：C

题目分析：A、氧化钙的俗称是生石灰，其化学式为：CaO，其化学式与俗名、名称不一致．

B、氢氧化钠俗称火碱、烧碱、苛性钠，其化学式为：NaOH，纯碱是碳酸钠的俗称，其化学式与俗名、名称不一致．

C、碳酸钠俗称纯碱或苏打，其化学式为：Na2CO3，其化学式与俗名、名称均一致．

D、酒精是乙醇的俗称，其化学式为：C2H5OH，CH3OH是甲醇的化学式，其化学式与俗名、名称不一致．

故选C．

点评：本题难度不大，熟练掌握常见化学物质的名称、俗称、化学式是正确解答此类题的关键．

单项选择题

长江公司2007年末应收账款余额为1000万元，假设该年年初应收账款余额为0；2008年确认坏账损失10万元，年末应收账款余额为800万元，2009年收回已转销的坏账6万元，年末应收账款余额为900万元，坏账准备提取比率为5%。该企业三年内计提“坏账准备”计入“管理费用”账户的金额累计为( )万元。

A．35
B．49
C．100
D．135
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单项选择题

In the second half of each year, many powerful storms are born in the tropical Atlantic and Caribbean seas. Of (91) , only about half a dozen (92) the p, circling winds of 75 miles per hour or more that give them hurricane status, and several usually (93) their way to the coast. There cause millions of dollars of (94) , and bring death to (95) numbers of people.
The great storms that hit the coast start (96) innocent circling disturbances hundreds, even thousands of miles out to sea. As they travel aimlessly over water (97) by the summer sun, they are carried westward by the (98) winds. When conditions are just (99) , warm, moist air flows in (100) the bottom of such a disturbance, moves upward through it and comes out at the top. In the (101) , the moisture in this warm air produces rain, and with it the heat is converted to energy in the form of p winds. As the heat increases, the (102) hurricane begins to swirl in a counter-clockwise motion.
The average life of a hurricane is only about nine days, but it contains almost (103) power than we can imagine. The energy in the heat released by a hurricane’s rainfall in a(n) (104) day would (105) the entire electrical needs of the United States for more than six months. Water, not wind, is the main (106) of death and destruction in a hurricane. A(n) (107) hurricane brings 6-to 12-inch downpours (108) in sudden floods. (109) is the powerful movement of the sea-the mountains of water moving toward the low-pressure hurricane center. The water level (110) as much as 15 feet above normal as it moves toward shore.

A．Finally

B．What is more

C．Worst of all

D．First of all
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