阅读理解。
Animal experts in Croatia say a bear has learned how to trick people to let him in by knocking at the
door.
They believe the 220- kilogram brown bear probably learned the trick while nudging (轻推) a door
to get it to open.
Experts have a guess that the nudging was mistaken by the owners for knocking and that the bear,
pleased by the result, repeated the trick.
The Loknar family from Gerovo in western Croatia said the bear had knocked at their door three
times and they were now refusing to answer the door.
''We jumped out of the window as he came in through the door and went into the kitchen to take
some food for the first time." Mum Nevenka Loknar told a reporter from a local newspaper. "I opened
the door and saw him standing there and I didn't believe my eyes at first, then I ran for it as he walked in
as if it was the most normal- thing in the world."
Bears are a common thing in the woods around here, but no one has ever heard of a bear that knocks
at the door.
Mum Nevenka Loknar said, "The bear is so intelligent. It's incredible. We've tried to put up lots of
obstacles to stop him coming in, like a wire fence but he still gets through. I wouldn't be surprised if he
knew how to use wire cutters (钢丝剪)."
1. According to experts in Croatia, how did the bear learn the trick?
A. By knocking at the door several times.
B. By accident.
C. By learning from the owner of a family.
D. By imitation.
2. What does the underlined word "it" in paragraph 5 refer to?
A. Eating at the kitchen.
B. Knocking at the door.
C. Walking into the house.
D. Answering the door.
3. It is ________ in Gerovo that a bear knocks at the door.
A. unusual
B. a troubling problem
C. common
D. an exciting experience
4. Mum Nevenka Loknar was surprised that the bear _____.
A. didn't attack her family
B. knew how to use wire cutters
C. jumped across her wire fence three times
D. was clever at getting through the obstacles
铜
干冰
氯化铜
金刚石