问题
填空题
按规律写数字。
1. one __________ five seven __________ __________
2. five __________ fifteen twenty
3. two four __________ eight __________ __________ fourteen
4. twelve __________ fourteen __________ sixteen __________ eighteen nineteen
答案
1. three, nine, eleven 2. ten 3. six, ten, twelve 4. thirteen, fifteen, seventeen
