题目内容：

Earthquake rescue robots have experienced their final tests in Beijing. Their designers say that with these robots, rescue workers will be able to have more time to save more lives during an earthquake.

This robot looking like a helicopter（直升机）, is called the detector-bot . It's about 4 meters long, and it took about 4 years to develop the model. Its main functions（作用）are to collect information from the air, and send goods of up to 30kilos, to people stuck in an earthquake.

This robot has a high quality 360 degree panoramic camera. It can work day and night and will also be able to send the latest pictures from the quake area. Dr. Qi Juntong, Chinese Academy of Science, said, "Unlike other automatic machines, the most important feature of this robot is that it doesn't need a distant control. We just set the information of the earthquake-struck area on it, and then it takes off, and lands by itself. It flies as high as 3,000 meters, and as fast as 100 kilometers per hour. "

This robot has a different function --- it can change as the environment changes. Its main job is to search for any signs of life in places where human rescuers are unable to go.

As well as a detector（探测器）that finds victims（遇难者）and detects poisonous gas, a camera is placed in the 40 centimeter long robot, which can work in the dark.

Another use for the rescuers is the supply bot, with its 10-meter-long pipe. People who are caught in the ruins will be able to get supplies including oxygen and liquids.

Experts have said that the robots will enter production, and serve as part of the national earth- quake rescue team as soon as next year.

1.Which of the following statements about the robot is true according to the passage?.

A. It hasn't been put into production so far.    B. It is a machine with a length of 10 meters.

C. It is a machine carried by a helicopter.    D. It weighs about 30 kilos.

2.Dr. Qi Juntong thinks this robot is different from the others mainly because _____.

A. it has more functions

B. it has a more advanced camera

C. it can change as the environment changes

D. it can work by himself once given the information

3.The underlined word "which" in paragraph 6 refers to_____.

A. a camera    B. a detector

C. a rescuer    D. a doctor

4.What is the passage mainly about?

A. The appearance of the robot.    B. An introduction to the robot.

C. The reason for making the robot.    D. Some information about earthquakes.