作时间状语 Walking along the street, I met Mary. (=While I was walking along the street, …) Hearing the news, they all jumped with joy. 作原因状语 Being tired, I stopped to take a rest. (=Because I was tired, …) Not knowing her address, we couldn’t get in touch with her. 由于不知道她的地址,我们无法和她联系。
听到这个消息时, 他们都高兴地跳了起来。