watch 侧重“观看”,强调看活动的,非静止的画面,
如看电视watch TV,看球赛watch a match.

look “看”,强调看的动作,为不及物动词,因此要表示“看.”,必须加介词at
Look! The bus is coming.
Please look at the blackboard.

see “看见,看到”,强调看的结果
Please look at the picture. What can you see ?

read “阅读”,指看有文字内容的东西
如看书read a book,看报纸read a newspaper,看杂志read a magazine