have you ever heard of the story?hurry up ,and you'll not be late for school.the tree is so tall that we can't reach it.I was sweeping the floorwhen it began to rain.第三个： the tree is very tall.we can't reach it. 合并 the tree is——tall for us——reach。the tree is very tall.we can't reach it. 合并 the tree is too tall for us to reach。