there is a woman ____________?30 yeas old还是30-year-old?

都一样

30 yeas old=30-year-old
但是这里只能用30-year-old
用30 yeas old的话woman后要动词

30-year-old在这作 形容词

前者
30 years old 这里做后置定语，也可以这样以为 there is a woman (that is)
30 years old
30-year-old 是形容词没错，但不后置 只有说30-year-old woman
再如3-legged chair =a chair who has 3 legs

我觉得吧..是30 yeas old
因为后者是个形容词组..不知道是不是这样的.