1. In an airplane, I prefer an aisle seat than a window one.
    correct answer: b.

2. He pares a pair of pears.
    correct answer: b, a, c.

3. Her mom has three sisters, so she has at least three aunts.
    correct answer: b.

4. This piece of art work reflects the mind peace of author's.
    correct answer: b, a.

5. You can't probably stand it, but Chinese people eat dog meat and bear feet.
    correct answer: a.

6. His small plane sits still in that plain field.
    correct answer: b, a.

7. The state lawmakers gather in the state capital city and soon they will meet in the capitol building.
    correct answer: a, b

8. The school principal is very clear on his principles of managing this school.
    correct answer: a, b

9. Those salesmen sell cell-phones. The case of this newly designed phone smells a pleasing scent.
    correct answer: b, a, c

10. In your class of principle economics, you should have learned the concepts of capital principal and interest.
     correct answer: a, b

11. The wine seller is himself a connoisseur and collects quality wines from all over the world in his cellar.
     correct answer: b, a

12. It rains again. The king reigns in his kingdom, but can not do anything about weather. No one can rein the weather conditions. 
      correct answer: b, c, a

13. This vehicle has a good brake device and it is rare for for it to break down.
     correct answer: b, a

14. He rowed a boat in the lake, while his sister rode a bike on the road along the lake side.
     correct answer: c, a, b

15. Nowadays you must pay a dear price for a license of deer-hunting.
     correct answer: b, a

16. As soon as he uses a real bait, he quickly hooks a fish and reels it in.
     correct answer: b, a

17. The cord of this wine bottle is a circle and he draws a chord on it.
     correct answer: b, a

18. The reporter was right there, observing the whole rite and deciding to write about it afterwards.
     correct answer: a, c, b

19. At the fair, they paid a fair price for everything they purchased.
     correct answer: a, a.

20. Right after the long hours of negotiation in which he took a major role, he was so hungry and took a bread roll to stuff his mouth.
      correct answer: b, a.

Why did the cat run away from the tree? Because it saw the tree bark.

A cat is afraid of a dog, supposedly. "bark" means stem of a tree, but "bark" also means the sound of a dog cry (barking dog). Here it is used as a pun.

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