比較以下句子,再研究一下,你的問題就解決了：
This book is interesting to read == It is interesting to read this book
It is easy to do this job== This job is easy to do.
You are easy to teach=== It is easy to teach you
These old people are difficult to take care of === it is difficult to take care of these old people.
--------現(xiàn)在明白了嗎?a good day to you.------------