spied on

• v. 窥探(订梢；密切观察)

spied on的用法和样例：

例句

1. He was expelled from the country for spying on their naval bases.
   他因刺探该国海军基地的情报而被驱逐出境。
2. He often went to spy on her, but he never dared to let her see him.
   他经常窥探她的行动，但从未敢让她发现自己。