七年级的英语阅读理解题,正确率要求90%以上,

七年级的英语阅读理解题,正确率要求90%以上,
Today,there are more than 100 kinds of dogs in the world.Many people like to have dogs as their pets.Dogs are friends of man because they are lovely and they are faithful to their masters.
Dogs can do a lot of work for man.They play with us.They hunt with us.They also keep door for us.But long ago,dogs all over the world were wild(野生的).
All dogs have the same ancestor.People believe that a dog’s ancestor may be a wolf.Other animals,such as the fox,came from this ancestor,too.Millions of years ago,man began to feed and train wild dogs.The strong dogs became working animals.Working dogs had many kinds of jobs.They could help people to pull heavy things.They learned to keep an eye on the sheep and other small animals.They could help people in the war(战争).Some dogs were not strong.But they could help man hunt for game.Other dogs were the best as pets.
（ ）15.People like dogs because ________.
A.they are only our pets B.they are wild
C.they could play tricks D.they are lovely and faithful
（ ）16.The underlined word ancestor means _______.
A.朋友 B.敌人 C.祖先 D.家人
（ ）17.According to the passage,a wolf may be a _______ ancestor.
A.man’s B.dog’s C.fox’s D.dog and fox’s
（ ）18.Dogs appeared on Earth ______.
A.hundreds of years ago B.thousands of years ago
C.millions of years ago D.not long ago