树立自信应该用“set up”还是“build up”

树立自信应该用 build up

举例：

You must build up your confidence.
你必须树立自信。

build up
set up是 设置 的意思

2者皆可

我用build up

树立自信心
build up self-confidence
build up self-confidence树立自信心 ...

build up

build up