What could be simpler than shaking fruit

题目：

     What could be simpler than shaking fruit from a tree? Well, the job is a lot more difficult than you

might think. There is a right way and a wrong way to shake a fruit tree. And a person who is a good

apple tree shaker may not be a good cherry tree shaker. Different fruits take different shakes .

     As a rule, a slow hard shake is best. This makes the fruit fall much faster than a light; quick jiggle.

Most fruits have a set number of shakes per minute that will do the best job of getting them out of the

tree and onto the ground. To shake down plums, try shaking the tree four hundred times per minute,

moving the tree two inches at each shake. Experts say you'll get three times more fruit from the tree than

you will if you shake eleven hundred times per minute at one inch per shake. Cherries, because they are

smaller, need more shaking. A good rate of shaking seems to be about twelve hundred shakes per minute. Apples, like plums, need four hundred shakes.

     Of course, some people may choose to take no notice of all these expert directions for shaking fruit.

Keeping track of all the numbers can be enough to drive some people up a tree.

1. This passage is about ______.

A. eating plums                      

B. how to shake fruit from a tree

C. the value of fruits and vegetables      

D. ways in which people shake

2. A smaller fruit tree normally requires ______.

A. more people        

B. less shaking

C. two people per tree    

D. more shaking

3. The writer ends this story with ______.

A. a serious thought  

B. a suggestion for other ways to get fruit from trees

C. a joke            

D. a warning