After supper,he kept on _____ (play) computer ganes.Be careful ______ (not walk) on the ice.
问题描述：
After supper,he kept on _____ (play) computer ganes.
Be careful ______ (not walk) on the ice.
答
on是介词，后面要加doing形式
be careful to do小心做某事，否定直接在to前加not
答
playing
not to walk