you'd better___(keep)the fire burning in the evening
问题描述:
you'd better___(keep)the fire burning in the evening
she opened the door ___(let)the children come
答
1.keep
you'd better do sth 表示建议“你最好做某事”,do为动词原形
2.to let
不定式to接动词原形,表示目的"目的是"