题目内容：

The scientist from the Lockheed Space Company work in Felton, California, with the help of a computer．But the computer is placed in Sunnyside, about 80 kilometers away．What scientists input (输入) is sent by telephone lines to the computer, and after a time, copies of the designs are needed back in Felton as quickly as possible Lockheed people have tried several ways of sending the prints, but the most effective seems to be by pigeon．Are pigeons really used to carry messages in these days? They are, and they send the prints faster and cheaper than any other way．

Human messengers are much more expensive and slower than the pigeons．The road to Felton goes through the mountains, and the driving is not easy．An electronic printout (电子打印输出) system could do the work in Felton, but at a cost of 10 dollars a print．Pigeons carry the designs for about 1 dollar each．

Now Lockheed people have ten pigeon messengers．The pigeons do the work, and they have made Lockheed more famous．You can often read the news about pigeons in the newspapers around the world．

1.The passage is mainly about ___________________．

A． Felton, California

B． the scientists

C． how to work with computers

D． sending prints by pigeon

2.This story is unusual because pigeons ____________________．

A． don’t like carrying things

B． are often expensive to keep

C． seem out of place in the space age

D． aren’t friendly to the scientists

3.Something that’s effective ________________________．

A． usually costs more

B． is something that works

C． is often unhappy

D． is often done by animals