题目内容：

Scientists at Royal Holloway, University of London  and Queen Mary, University of London have discovered that bees learn to fly the shortest possible route between flowers even if they discover the flowers in a different order. Bees are effectively solving the “traveling salesman problem”, and they are the first creatures found to do this.

The traveling salesman must find the shortest route that allows him to visit all locations on his route. Computers solve it by comparing the length of all possible routes and choosing the shortest, and it can keep computers busy for days. However, bees solve it without computer assistance using a brain the size of grass seed. Dr. Nigel Raine, from the School of Biological Sciences at Royal Holloway explains, “Bees solve traveling salesman problems every day. They visit flowers at multiple locations and because bees use lots of energy to fly, they find a route which keeps flying to a minimum. ”

The team used the computer to control artificial flowers to test whether bees would follow a route defined by the order in which they discovered the flowers or if they would find the shortest route. After exploring the location of the flowers, bees quickly learned to fly the shortest route.

As well as improving our understanding of how bees move around the landscape pollinating(授粉)crops and wild flowers, this research, which is due to be published in The American Naturalist, has other applications. Our lifestyle relies on networks such as traffic on the roads, information flow on the Web and business supply chains. By understanding how bees can solve their problems with such a tiny brain, we can improve our management of these everyday networks without needing lots of computer time. Dr. Raine adds, “Despite their tiny brains, bees are capable of extraordinary feats of behavior. We need to understand how they can solve the traveling salesman problem without a computer. ”

1. What would be the best title of the passage?

A. Bees help salesmen travel

B. Tiny-brained bees solve a complex mathematical problem

C. How bees discover the flowers

D. How to solve the “traveling salesman problem”

2.We may infer from the second paragraph that the “traveling salesman problem” 　　　.

A. can be solved by a computer easily

B. can’t even be solved by a computer

C. can puzzle both people and computers

D. remains to be solved by scientists

3. The main purpose of the last paragraph is to　　　.

A. provide further proof for the research

B. tell us how bees can fly the shortest route between flowers

C. tell us how the research about bees’ flying route was conducted

D. explain the importance of the research

4. It can be concluded from the passage that　　　.

A. all creatures are smarter than computers

B. the research about bees’ flying route can be applied to many fields

C. our networks are more complex than bees’ ones

D. with the help of the computer we can find out how bees can solve the “traveling salesman problem”