2016-2017学年 人教版 必修5 unit3 Life in the future Grammar 课件 (12)
2016-2017学年 人教版 必修5 unit3 Life in the future  Grammar 课件 (12)第2页

Look at the sentence in the reading passage.

Worried about the journey, I was unsettled for the first few days. In the sentence the past participle is used as the adverbial. It is a way of joining two clauses together: As I was worried about the journey, I was unsettled for the first few days.