I find these problems are easy ____a.to be worked out b.to work t_英语解答

I find these problems are easy ____
a.to be worked out b.to work them out
c.to work out d.to be worked them out
选C 表是被动为什么不选A呢?

人气：163 ℃　时间：2020-03-22 13:58:14

解答

具体原因我也说不清,但有很多这样的例子：
the book is easy to read
the movie is good to watch
the job is fun to do
your voice is nice to hear