题目内容：

Self-driving vehicles will rely on cameras, sensors(传感器) and artificial intelligence (AI) to recognize and respond to road and traffic conditions, but sensing is the most effective for objects and movement in the neighborhood of the vehicle. Not everything important in a car’s environment will be caught by the vehicle’s camera. Another vehicle approaching at high speed on a collision (碰撞) track might not be visible until it’s too late. This is why vehicle-to-vehicle communication is undergoing rapid development. Our research shows that cars will need to be able to chat and cooperate on the road, although the technical challenges are considerable.

Applications for vehicle-to-vehicle communication range from vehicles driving together in a row, to safety messages about nearby emergency vehicles. Vehicles could alert each other to avoid collisions or share notices about passers-by and bicycles.

From as far as several hundred metres away, vehicles could exchange messages with one another or receive information from roadside units（RSUs）about nearby incidents or dangerous road conditions through 4G network. A high level of AI seems required for such vehicles, not only to self-drive from A to B, but also to react intelligently to messages received. Vehicles will need to plan, reason, strategize(制定策略) and adapt in the light of information received in real time and to carry out cooperative behaviours. For example, a group of autonomous vehicles might avoid a route together because of potential risks, or a vehicle could decide to drop someone off earlier due to messages received, a foreseen crowding ahead.

Further applications of vehicle-to-vehicle communication are still being researched, including how to perform cooperative behaviour.

1.What is the first paragraph mainly about?

A. The reasons for the accidents by self-driving vehicles.

B. The importance of artificial intelligence of self-driving vehicles.

C. The reasons for developing communication between self-driving vehicles.

D. The research about applications for self-driving vehicles.

2.What does the underlined word “alert” mean in Paragraph 2?

A. Alarm.    B. Blame.

C. Ignore.    D. Govern.

3.What can we learn about roadside units (RSUs)?

A. They recognize the vehicles on the road.

B. They can improve bad road conditions.

C. They take control of the passing vehicles.

D. They serve as efficient information stations.

4.What is the main idea of the text?

A. Different kinds of vehicle communication.

B. Importance of high level AI.

C. Vehicle-to-vehicle communication.

D. Ways to improve our communication with vehicles.