英语基本语法小问题求教高人!

问题描述:

英语基本语法小问题求教高人!
Other ways to write regularly include keeping a diary,writing a short story and summarizing the daily news.
本句中 keep,write,summarize为什么都用了-ing形式?

因为这几个词在句中都做include的宾语,include后用动名词做宾语.就像enjoy doing sth.一样.