这句话为什么grow become 要加ing 做什么成分

问题描述:

这句话为什么grow become 要加ing 做什么成分
the themes of the stroy are to do with children growing up and becoming more serious

The themes of the stroy are to do with children growing up and becoming more serious.
=The themes of the stroy are to do with children who are growing up and becoming more serious.
growing up and becoming more serious是两个并列的现在分词短语,在句中做定语,相当于一个定语从句.