填空题 Greatly (encourage) 1 by his friends, Jack has signed up for the singing competition.
【正确答案】
【答案解析】encouraged [考点] 动词-ed短语作状语
[解析] 本句的意思是：在朋友的大力支持下，杰克已经报名参加了歌唱比赛。Greatly encouraged by his friends作状语，修饰句子的动词。