Question

【题目】A new smart phone system under development can locate you even when you’re inside a building, which GPS can't do. While the concept sounds powerful, it’s not yet clear how practical it might be.

The set-up, called SurroundSense, sends information from cameras and microphones—gear in the latest smart phones—to a server that produces a fingerprint of the location.

“You can’t tell much from any of the measurements individually, but when combined, the optical (光学的), acoustic (声学的) and motion information creates a unique fingerprint of the space,” said Ionut Constandache, a student in computer science.

The system distinguishes between two indoor spaces in this manner: It knows that a bar is likely to be dark and noisy and people move little, sit a lot, whereas a department store will be brightly lit, contain vibrant colors, and will see a lot of people moving up and down passages. The more the system is used, the more it learns about specific places.

More work is needed before the set-up would be ready for prime time, however. For now, it can’t work if a person’s cellphone is in a handbag or otherwise unable to employ the camera. Finally it would be best served if paired with phones that were worn on the wrist or hung around the neck. Batteries, too, are a problem.

Students on the research team went out across Durham, North Carolina, with their cellphones collecting data in different types of businesses. The students mirrored the actions of the selected customers so that they would not prejudice the measurements.

“We went to 51 different stores and found that SurroundSense achieved an average accuracy (精确性) of about 87 percent," Constandache said.

“As the system collects and analyzes more and more information about a particular site, the fingerprint becomes more precise,” said Romit Roy Choudhury, professor of computer engineering. “Not only is the ambience different at different locations, but also can be different at different time at the same location.”

【1】We can infer from the first paragraph that GPS .

A. can find you wherever you are

B. can make too much loud noise

C. can only find outside things

D. isn’t really practical yet

【2】Why did students mirror the actions of the selected customers?

A. To get a reasonable result.

B. To collect data in different ways.

C. To receive information about a particular site.

D. To learn more about specific places.

【3】The underlined word “ambience” in the last paragraph may mean .

A. the fingerprint of the location

B. the character of a place

C. the existence of people

D. the area of store

【4】The main idea of the passage is about .

A. comparing GPS with a smart cellphone

B. the development of cellphones

C. a cellphone knowing where you are

D. what kind of future cellphones face

Answer 1

【答案】

【1】C

【2】A

【3】B

【4】C

【解析】

试题分析：文章介绍了一种新的智能手机定位系统。这个系统甚至能定位到建筑物内的人的位置。这看起来像是一个疯狂的概念，因为它的实用性还未得到验证。

【1】推理判断题。根据第一段“can locate you even when you’re inside a building, which GPS can't do”可知，一个新的手机系统能够定位大楼内的人的位置，这是GPS办不到的，由此推知，GPS只能定位露天的地方，故选C。

【2】细节理解题。根据倒数第三段“The students mirrored the actions of the selected customers so that they would not prejudice the measurements.”可知，试验中，学生模仿被选中的消费者的动作，是为了减少测量的偏差，故选A。

【3】猜测词义题。根据“...more information about a particular site, the fingerprint becomes more precise”可知，这里说的是收集并分析同一地点的信息越多，指纹识别就会变得越精确，不同地点有不同的环境，同一地点在不同的时间，它的周围环境也有可能不同，故选B。

【4】主旨大意题。根据第一段“ A new smart phone system under development can locate you even when you’re inside a building”和后面几段的首句“The set-up, called SurroundSense, ...The system distinguishes between two indoor spaces in this manner ...More work is needed before the set-up would be ready for prime time”可知，文章主要介绍了 一个新的手机定位系统，故选C。