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一.概念:
数词分两类:基数词和序数词.表示数目的词叫基数词,表示须序的词叫序数词.
二.相关知识点精讲
1.基数词
1）基数词一般可写成如345或three hundred and forty-five。
2）基数词一般是单数形式，但遇下列情况，常用复数：
a. 与of 短语连用，表示概数，不能与具体数目连用，如scores of people 指许多人；
b. 在一些表示"一排"或"一组"的词组里。例如：
They arrived in twos and threes. 他们三三两两的到了。
c. 表示"几十岁"。
d. 表示"年代"，用 in +the +数词复数。
e. 在乘法运算的一种表示法里，如Three fives is（are）fifteen。
2.序数词
序数词的缩写形式如first---1st second---2nd thirty-first---31st等。
3.数词的用法
1）倍数表示法
a. 主语+谓语+倍数（或分数）+ as + adj. + as。例如
I have three times as many as you. 我有你三倍那么多。
b. 主语+谓语+倍数（分数）+ the size （amount，length…） of…。例如：
The earth is 49 times the size of the moon. 地球是月球的49倍。
c. 主语+谓语+倍数（分数）+ 形容词（副词）比较级+ than…。例如：
The grain output is 8 percent higher this year than that of last year. 今年比去年粮食产量增加8%。
d. 还可以用by+倍数，表示增加多少倍。例如：
The production of grain has been increased by four times this year. 今年粮食产量增加了4倍。
2）分数表示法的构成：基数词代表分子，序数词代表分母。分子大于1时，分子的序数词用单数，分母序数词用复数。例如：
1/3 one-third； 3/37 three and three-sevenths.
三.巩固练习
1.______ martyrs have heroically laid down their lives for the people.
a. Thousand upon thousand of b. Thousand and thousands of
c. Thousands upon thousands of d. Thousand and thousand of
2.They received ______ of letters about their TV programs.
a. dozen b. dozen and dozen c score d. dozens
3.Who is that man,______ in the front row?
a. one b. the one c. first d. the first
4.We have produced ______ this year as we did in 1993.
a. as much cotton twice b. as twice much cotton
c. much as twice cotton d. twice as much cotton
5.The earth is about ______ as the moon. |
