On; in contact with and supported by a surface.

在……上；与表面接触并由其支撑。

At the time of; immediately after; on the occasion of.

在……时；一……就；紧接着。

Onto or against; directed at or pressing on.

到……之上或抵着；朝/向……施力。

About; concerning; with regard to (formal).

关于；就……而言（较正式）。

Affecting or directed at; impending upon or closing in.

作用于/指向；迫近；临到……身上。

Depending on; based on; using or by means of.

• In oaths or assurances: upon my word, upon my life.

取决于；基于；凭借；通过。

• 用于誓言/保证：凭我的话，拿我的性命起誓。