阅读理解。

     It's hard to avoid looking like a fool on April Fool's Day.On April 1 each year, people play

tricks on each other.These tricks are usually silly rather than mean.Classmates sometimes tie

each other's shoelaces to their chairs.Teachers might hand out an impossibly difficult surprise

test that scares students before they realize it's only a joke.Newspapers announce fake contests

(such as "Win an elephant!") and report on fake stories (like "UFO" lands in New York City)．

     Forget gifts, songs and special foods-those are for the other holidays of the year.On April

Fool's Day, the only tradition is to laugh (and maybe to cause a little bit of trouble)．

      One April Fool's Day, when I was in high school, a group of students in my class played a

very clever and funny trick on the teachers.They bought some chickens and set them free in our

school cafeteria.The chickens ran all round the school, in and out of classrooms and under our

feet. Feathers were flying everywhere.

     Teachers began running after the chickens, trying to catch them.Finally, they caught four of

them.But the chickens were wearing numbered tags (商标) around their necks, and the teachers

discovered that they had only caught chickens No.1, 2, 3, and 5.Where was chicken No.4?

     The teachers looked and looked.They couldn't find another chicken.After a few hours, they

realized that the students had played another joke on them: There were only four chickens in the

first place! They've been tricked by the numbers on the chickens.

     It's been a long time since I was in high school, but that April Fool's Day remains one of my

 favorite memories from those years.

1．What can we infer from the first paragraph on April Fool's Day?

A．Everyone is hard to avoid being fooled on April Fool's Day.

B．Students play jokes on teachers on April Fool's Day.

C．Teachers play tricks on students on April Fool's Day.

D．Newspapers often cheat people.

2．Why did students set chickens free?

A．They wanted to let chickens free.

B．They wanted to let chickens run all round the school.

C．They wanted to see feathers flying.

D．They wanted to play a trick on teachers.

3．How many jokes did the students play on teachers?

A．One.  

B．Two.

C．Three.  

D．Four.

4．What's the title of the passage?

A．An unforgettable April Fool's Day

B．April Fool's Day

C．The origin of April Fool's Day

D．What do people do on April Fool's Day?