下面是一句考研完型填空的题目,28出填for example,但是这个后面不是要接句子吗?可是题目后面是短语啊

下面是一句考研完型填空的题目,28出填for example,但是这个后面不是要接句子吗?可是题目后面是短语啊
However,the typical teenage lifestyle is already filled with so much competition that it would be 27 to plan activities in which thereare more winners than losers,28 ,publishing newsletters with manystudent-written book reviews,29 student artwork,and sponsoring book discussion clubs.