a. in operation or operational
a. (of events) planned or scheduled
r. indicates continuity or persistence or concentration
r. in a state required for something to function or be effective
prep. 在...之上
adv. ...上去
a. 正起作用的
[计] 打开
1. The book is on the table.
这本书在桌子上。
2. I will meet you on Friday.
我星期五会见你。
3. She put her phone on silent.
她把手机调成静音。