【解析】
1. 基数词变序数词有如下规则:
1-3为特殊变形:one→first,缩写1st;two→second,缩写2nd;three→third,缩写3rd;
4-10通常在词尾加-th:four→fourth(4th),five→fifth(5th),six→sixth(6th),seven→seventh(7th),eight→eighth(8th),nine→ninth(9th),ten→tenth(10th);
以ve结尾的基数词,变ve为f加-th:twelve→twelfth(12th);
以y结尾的整十数,变y为ie加-th:twenty→twentieth(20th);
几十几的数词变序数词,仅将个位改为序数词:twenty-one→twenty-first(21st),twenty-two→twenty-second(22nd),twenty-three→twenty-third(23rd);
部分基数词直接加-th:fifteen→fifteenth(15th),eighteen→eighteenth(18th)。
【答案】
1. first; 1st
2. second; 2nd
3. third; 3rd
4. fourth; 4th
5. fifth; 5th
6. sixth; 6th
7. seventh; 7th
8. eighth; 8th
9. ninth; 9th
10. tenth; 10th
11. twelfth; 12th
12. fifteenth; 15th
13. eighteenth; 18th
14. twentieth; 20th
15. twenty-first; 21st
16. twenty-second; 22nd
17. twenty-third; 23rd
【知识点】
基数词变序数词;序数词缩写
【点评】
本题考查英语数词中基数词转换为序数词的规则及序数词的缩写形式,属于基础考点,需牢记特殊变化和一般规律,熟练掌握常见数词的转换。
【难度系数】
0.8