mr.black had two cats. one was very big and the other was quite small. he loved them very much .one day ,mr.green, one of his friends, came to visit him. he saw two holes in the door. a big one anda small one. mr.green asked.''my dear friend, why are there twoholes in your door?''''let my cats go in ang out,'' answered mr.black. ''but why are there two holes? isn't one enough?''asked his friend. ''how can the big cat go through the small hole?''he said.对的打钩,错的打叉1.mr.black had three cats.2.there were two holes in the door.3.mr.black thought the big cat could only go throgh the big hole and the small at could only go through the small hole.4.in fact, one big hole is enough.5.mr.black was very smart.