a.

1. 富裕的[R]
   My uncle is quite well-off.

   我叔叔很富有。

   Most people are better-off than ten years ago.

   大多数人比十年前更富有。

2. 富于……的[F][（+for）]
   You're well-off for coal, I hope.

   但愿你们有足够的煤。

3. 幸运的[F]
   Jack doesn't know when he is well-off.

   杰克身在福中不知福。