4.6g某物质在空气中完全燃烧生成8.8gCO2和a.4gH2O,则 (1)共消

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问题:

4.6g某物质在空气中完全燃烧生成8.8gCO2和a.4gH2O,则

(1)共消耗氧气多少克?______

(2)计算说明该物质的组成及各元素的质量.______

(三)写出其化学式.______.

考点:质量守恒定律化学式的写法和意义
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下列哪项不符合中期妊娠水囊引产()

A.放置时间不超过24小时

B.一般放置一个水囊

C.两次放置间隔时间应为48小时

D.注水量为300~500ml

E.放置部位最好在子宫下段

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蘑菇的有性孢子是()

A、外生的担孢子

B、外生的分生孢子

C、内生的子囊孢子

D、内生的接合孢子

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( )表示同一对象不同时间之间的对比。

A.动态相对数
B.比例相对数
C.比较相对数
D.结构相对指标

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Tyrus Raymond Cobb was born in Narrows, Georgia in 1886. He grew up in Royston, Georgia with his parents, William and Amanda Cobb. Ty began playing baseball as a child and was a professional baseball player before the age of twenty. Cobb played mostly for the Detroit Tigers and served as their player manager from 1921~1926. He played baseball for a total of twenty-four years before retiring. Cobb won twelve American League batting titles and was known for his great speed and excellent batting skills. He used both of these as weapons on the baseball diamond. Cobb still holds the record as the all-time leading hitter in the major leagues, with a 367 lifetime batting average. His career total of 4 191 hits was the major league record until it was broken by Pete Rose in 1985.
Ty Cobb was elected to the Baseball Hall of Fame in 1936 and was one of the first five players to receive this award. Cobb died in Atlanta, Georgia on July 17, 1961 and will be remembered as the great "Georgia Peach".

Ty Cobb’s interest in baseball began ______.
[A] in Philadelphia.
[B] when he lived in Detroit.
[C] at the University of Georgia.
[D] as a young boy.

题型:问答题

我国现行标准规定的φ5.5~φ10的线材精度等级有ABC,A级精度对直径允许偏差定为(),对不圆度允许偏差定为0.5mm。

A.±0.4mm

B.±0.5mm

C.±0.6mm

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