问题 多选题

“拯救生命是第一位的”.图为4月15日来自广东的消防官兵手提生命探测仪,在废墟中搜索生命的信号.为搜索埋在废墟下的幸存者,还用了许多搜救犬.搜救犬能根据人体发出的气味发现幸存者.从微观的角度分析搜救犬能发现幸存者的原因是(  )

A.分子的质量很小

B.分子的不断运动

C.不同分子性质不同

D.分子间有间隙

答案

A、搜救犬能发现幸存者的原因是因为分子的不断运动,和分子质量小无关,故A错误;

B、搜救犬能发现幸存者的原因是因为分子的不断运动,故B正确;

C、搜救犬能发现幸存者的原因是分子在不断运动,且不同分子性质不同,人体发出不同气味的分子,故C正确;

D、搜救犬嗅到气味和分子间有间隔无关.故D错误.

故选BC.

阅读理解

阅读理解。

     Driving speeds have largely stabilized, and nowadays, safety concerns are important and reducing

road accidents to minimum is a must. So, automakers are focused on safety systems more than ever

before.

Given the emphasis on improving safety, it's possible that well-known phrases such as "live fast and

die young" may lose their meaning as innovative (创新的) new devices are built into cars and trucks

and other things that go.

     Many of the new safety systems that are being added to high-end vehicles are computer-assisted

technologies that transfer some of the vehicle's operations to the vehicle itself, rather than relying only

on the driver's decision-making skills.  

     For example, predictive brake assist is an in-vehicle feature that prepares the vehicle for braking

when its built-in sensors detect a potential object ahead. The predictive brake assist basically places

the vehicle's braking system on alert, which helps the system to slow down the car in as little time and

as short a distance as possible.

     Other in-vehicle sensors will detect moving and still objects and will even distinguish the objects

based on simple patterns, such as other vehicles vs. a person.

What's more, built-in "active systems", i.e., predictive precollision (可预测碰撞) systems, will provide

drivers with advance detection of potential contact between vehicles. These systems compute the

relative movement of the objects and detect possible dangerous intersections (交点).

     What technological developments have enabled innovations like predictive precollision systems?

Essentially, these so-called active systems are the result of vehicle-to-vehicle and vehicle-to-infrastructure

communications.

     These communication links allow highways to provide a vehicle's owners with services such as renting

a movie during the trip, as well as reduce reaction delays when medical care is needed due to a crash.  

Despite these new technologies, drivers cannot take safety for granted.

     Until all vehicles are fully automated, it is the drivers themselves who are responsible for operating

their vehicles and obeying traffic laws designed to keep roadways secure. So, keep your eyes on the

road and your hands on the steering wheel (方向盘).

1. "Predictive Precollision" can be used to _________. 

A. detect possible dangerous crossroads

B. compute the relative movement of the contacting vehicles 

C. brake the car automatically in as little time as possible

D. detect potential contacts between vehicles in advance

2. Which of the following statements is NOT true?

A. Advanced safety systems make driving an easier job.

B. Automakers pay more attention to safety system than before.

C. New advanced technology makes the vehicle operation rely only on the vehicle itself.

D. Drivers are still expected to drive carefully despite the built-in advanced safety system.

3. We can conclude that the new technology will _________.

A. put an end to road accidents

B. force people to obey traffic laws

C. see a wide use in the future

D. ensure the quality of medical care

4. Which of the following would best serve as the title for the passage?

A. Live fast, die young

B. New systems, safer driving

C. New technology, relaxed drivers

D. High-end vehicles, big innovation

单项选择题