像two-year-old中year不可以用复数吗

像two-year-old中year不可以用复数吗 two - year - old two - years -old two year old two years old 为什么 a four-year-old boy中的year可以不加复数,而分数two-thirds中连字符后的third 复合形容词可不可以加名词复数?类似：three two-year-old boys 能不能举几个例子 I am thirteen years old this year.(用two years ago代替this year two-year-old 与two years old有何区别 two years old与two-year-old的用法区别 all year round year要用复数吗 sixteen-year-olds可以直接使用,sixteen-year-old不可以直接使用后面要加boy? two( )twins. A. nine-years-old B. nine-year-old C. nine year Jim's little sister is only two ___ .A.year old B.old year C thirty-two year old,two与year间要不要连词符号?