In this sentence

①do sb a favourn.帮某人一个忙；恩惠

Synonymskindness, service, courtesy

在本句中，“do me a favour” 是极常见的日常请求短语，搭配后面的“and lend me...”，意为“帮我个忙，把昨天的笔记借我一下”。

• If you do someone a favour, never remember it; if someone does you a favour, never forget it.施恩莫图报，受恩莫忘怀。

②in favour of sb/sthn.赞成；支持

Synonymssupportive of, pro, backing

• I am in favour of animal rights as well as human rights. That is the way of a whole human being.我既支持人权，也赞成动物权益。唯有如此，方为一个完整健全的人。— Abraham Lincoln

③favour sth over sthv.较喜欢；偏袒

Synonymsprefer, lean toward, champion

• Those who favour comfort over truth often lose both in the end.那些偏好安逸而轻视真理的人，最终往往两者皆失。