2024年牛津上海版英语八年级上册寒假突破 数词2（含答案）

口诀解题 以一敌十 数词（2）
数词概述
数词表示数目多少或顺序先后，分为基数词和序数词；
基数词表示人和事物数目或数量的多少，如：four/thirteen/twenty/ninety-nine；
序数词表示顺序先后，如：first/second/third/fifth/forty-fourth；
数词可以用来表达编号、日期、年龄、年代、时刻、分数、小数、倍数等。
数词口诀（2）
子基母序，分子＞1，分母+s
in one's -ties，in the 1990s
有连字符-绝无s
口诀详解
子基母序，分子＞1，分母+s
用英文表达分数时，分子用基数词，分母用序数词，当分子大于1时，分母须用序数词的复数形式，要在词尾加s。（上子下母，前基后序：在数学中，分数线上面是分子，下面是分母；在英语中，前面的是分子，后面的是分母）
half：n. 一半 quarter：n. 一刻钟/四分之一
1/2 a half 或 one half
1/3 a third 或 one third
1/4 a quarter 或 one quarter 或 a fourth 或 one fourth
3/4 three quarters 或 three fourths
2/5 two fifths
2/9 two ninths
逢十的基数词的复数形式表示年龄和年代
in one's -ties（整十基数词的复数）：在某人几十多岁时。
in his twenties 在他二十多岁时
in one's twenties/thirties/forties/fifties/sixties/seventies/eighties/nineties
在某人二/三/四/五/六/七/八/九十岁时
in the 整十年份的复数或者所有格：在……世纪……年代。
in the 1990's = in the 1990s 读作：in the nineteen nineties
在二十世纪九十年代
有连字符-绝无s
基数词和其他名词组合可构成短语作定语，其中的名词用单数形式，短语中的各部分间要用连字符“-”来连接。
基数词-名词单数（-形容词）
He is an eight-year-old boy. VS He is eight years old.
a three-month-old baby 一个三个月大的婴儿
a five-minute walk = five minutes' walk 五分钟的步行
a two-month visit to Japan 一次对日本为期两个月的访问
a three-week trip around China 一次为期三周的中国之行
口诀解题示范
In our class, ________ of the students are boys.
A．three-fifths B．three-fifth C．third-fifth D．third-fives
分析：
观察ABCD四个选项可知本题考点是分数表达法，根据口诀子基母序，分子＞1，分母+s，通过子基母序排除CD，分子是three，3＞1，分母fifth要加s，排除B，得出答案，选A。
In his ________, Charles began to write and soon became famous.
A．twenty B．twenties C．twentieth D．twentieths
分析：
观察ABCD四个选项可知本题考点是逢十的基数词的复数形式表示年龄，根据口诀in one's -ties，直接得出答案，选B。
Cindy is ________ girl and she wants to be a teacher.
A．a 18-year-old B．an 18-years-old
C．an 18-year-old D．a 18 years old
分析：
观察ABCD四个选项可知本题考点是基数词-名词单数（-形容词）短语和冠词，根据口诀有连字符-绝无s，排除B。18是eighteen，根据口诀一个one欧洲人European用a（口诀解题 以一敌十 冠词1），eighteen ≠ European，eighteen前不用a，反之用an，排除A和D，最后得出答案，选C。
真题训练
One __________ of the students in our class chose to join the clubs after school. (three)
Only three __________ of the workers in this area can understand German. (five)
I found two __________ of the students didn’t finish the homework. (three)
Four __________ of the students have been to the exhibitions. (nine)
Five __________ of the students agreed that Peter should be the monitor. (twelve)
He went to study in the USA in his __________. (twenty)
Justin Bieber got popular among the teenagers in the world in his __________. (twenty)
He was a big man in his __________, smartly dressed in a suit and tie. (thirty)
My uncle used to work as an engineer and he became famous in his __________. (forty)
Tyrone went to live in Australia with his family in his __________. (fifty)
My grandma took up dancing as a hobby in her __________. (sixty)
Tom’s grandpa began to learn English in his __________. (seventy)
Bob’s grandpa is still working for the charity organizations in his __________. (eighty)
The old man, in his late __________, is too old to take care of himself. (ninety)
Nearly __________ of the students in your class took part in the English competition.
A．two-thirds B．two-three C．two-third D．two-threes
My neighbour Granny Wang had a lovely granddaughter in her __________.
A．fifty B．fifties C．fiftieth D．fiftieths
Our English teacher looks young. It’s hard to imagine she is already in her __________.
A．forty B．fortieth C．fourteen D．forties
About __________ of the students in our class were born in __________.
A．three forths; 1990s B．three-fourths; the 1990s
C．three-forths; the 1990s D．three fourth; 1990
__________ of the apples in the fruit bowl are big and sweet.
A．Two-third B．Second-three C．Two-threes D．Two-thirds
My aunt began to learn Japanese in her __________. It’s never too late to learn.
A．thirty B．thirtieth C．thirties D．thirteen
Alibaba CEO Jack Ma has decided to retire from his company in his __________．
A．fifty B．fifties C．fiftieth D．fiftieths
Water covers most parts of the earth. About __________ of the earth is covered with water.
A．one fourth B．a half C．one seven D．three quarters
It was a great honour for Tu Yoyo to win the Nobel Prize for medicine in her __________.
eighties B．eighty C．eightieth D．eightieths
__________, J. K. Rowling began to write the story of Harry Potter.
In 1990’s B．In 1990s C．In the 1990s D．In the 1990
This is a __________ zebra.
A．ten-mouths-old B．ten months old
C．ten-month-old D．ten-mouth old
About __________ of the middle school students’ parents in our country were born in the __________.
two-thirds;1980 B．two-thirds ;1980s
C．twice-threes;1980 D．twice-threes ;1980s
In the United States children start school when they are __________ boys and girls.
five-year-old B．five-years-old
C．five-year old D．five years old
—Gu Ailing, an __________ athlete, won two gold medals in the 2022 Beijing Winter Olympic Games.
—She is my hero!
A．18 years old B．18-years-old
C．18-year-old D．18 year old
Most of the basketball players in the club are in their __________ and they were born in __________.
A．twentieth; 1990 B．twentieth; the 1990s
C．twenties; 1990s D．twenties; the 1990s
The granny is __________. She can’t look after her __________ grandson.
A．80-year-old; 10 months old B．80 years old; 10-month-old
C．80-years-old; 10-months-old D．80 years old; 10 months old
答案：
1~14：
third
fifths
thirds
ninths
twelfths
twenties
twenties
thirties
forties
fifties
sixties
seventies
eighties
nineties
15：A
16~20：BDBDC
21~25：BDACC
26~30：BACDB