live by 靠...过活 live by doing or sth./n.
e.g.Jack lived by writing for a newspaper.
杰克靠给一家报纸写稿来维持生活.
live on
1.靠...生活;以...为食
（动物）以...为食；（人）靠...生活
2.live on靠吃---生活,靠---维持生活
live in
形容词 a.
1.住在受雇之处的
2.(未婚而)同居的