She's middle-aged. 她已到中年了。

A: Your mother is very young.

A: 你的母亲很年轻。

B: No, she's not. She's middle-aged.

B: 不，她不年轻了。她已到中年了。

A: Middle-aged? She's only about 40.

A: 中年？她才40岁上下。

B: 40 is middle-aged. 40 is old!

B: 40岁就是中年。40岁的人老了！

A: 40 is not old! Wait till you're 40.

A: 40并不老！等你到40岁就知道了。

B: I never want to be middle-aged.

B: 我永远也不想到中年。