（急!）：It isn't easy for him to work out this problem.I thought.(合并为一句)It isn't easy for him to work out this problem.I thought.(合并为一句)I ___ ___ it ___ easy for him to work out this problem.
问题描述：
（急!）：It isn't easy for him to work out this problem.I thought.(合并为一句)
It isn't easy for him to work out this problem.I thought.(合并为一句)I ___ ___ it ___ easy for him to work out this problem.
答
didn't think was
答
didn't think is
答
I thought that it wasn't easy for him to work out this problem.