1. up to : 从事于(坏事), 忙于, 胜任, 能做, 适合, 适于；
2. up and down : 到处；
3. up to date : 最近的, 最新的；
4. up for : 在选举中被提名供考虑, 在法庭受审；
副词
形容词
租房
What are you up to
进修
介词、副词和形容词用法（PREPOSITION, ADVERB, AND ADJECTIVE USES）
Up is often used with verbs of movement such as ‘jump’ and ‘pull’, and also in phrasal verbs such as ‘give up’ and ‘wash up’.
1. raise
e.g. up the ante