was+adj+for+sb+to+do+sth造句？

1. It was difficult for him to understand the math problem.（他理解这个数学问题很困难。）2. It was important for her to study hard for the exam.（她为了考试而努力学习很重要。）3. It was easy for them to solve the puzzle.（对他们来说解决这个谜题很容易。）4. It was ...