The _ boy is Tom's brother.A 8-year old B 8 years old C 8year old D 8 years' old 请说明理由不知为什么

The _ boy is Tom's brother.A 8-year old B 8 years old C 8year old D 8 years' old 请说明理由不知为什么
The _ boy is Tom's brother.A 8-year old B 8 years old C 8year old D 8 years' old 请说明理由
不知为什么

The _ boy is Tom's brother.A 8-year old B 8 years old C 8year old D 8 years' old 请说明理由不知为什么
选 B 8 years old
8 years old = 8-year -old 8岁

A 8-year old 是一个复合形容词，可以作定语；而8 years old 只能做表语； C 8year old D 8 years' old 的说法是错误的

答案是：A 8-year old
只有A能做定语 B 8 years old 只能作表语
“答案是D，不知为什么”？？？答案肯定错了！
而且 A最好是8-year-old前后都要破折号。

A