It' hard to solve this problem. It' hard to do the housework. It' hard to make a model. It' hard to answer this question. It' late to go to school now.
用"It is+adj+to do sth" 造两个句子。 It's important to study English well. It's great to climb mountain at the weekend. 希望帮助到你,若有疑问,可以追问~~~ 祝你学习进步,更上一层楼!(*^__^*)