题目内容：

When asked how technology might improve the lives of people with vision impairments (视力障碍), Joann Becker presented a misleadingly simple challenge. “Well,” the vision impairments tech specialist recalls saying. “I’d like to be able to find my bus slop through Be My Eyes”.

Be My Eyes, which went live in 2015, establishes a direct video connection between visually impaired users and sighted volunteers. The assumption is simple: Many people who are blind don’t need any actual assistance in completing their daily tasks, but merely need a little help.

A sighted volunteer might be asked to help identify which of two cans contains tomatoes. In this case, the visually impaired user can cook a meal just fine on his/her own-all he/she needs is a quick confirmation that he/she has the correct can. The model appears to be working; more than 540,000 volunteers and nearly 40,000 people with low vision are registered on the app.

“An elderly woman can now help a visually impaired technician set up his computer,” says founder Hans Wiberg, who has very low vision. “She doesn’t need to know a thing about computers. She only needs to read what is presented on the screen. Then he can do the rest.”

Early assistive technology centered on dedicated devices (专用设备), because of the niche market (缝隙市场), which sold for hundreds or even thousands of dollars. But the smartphone, multipurpose and near-universal, has completely changed the economy of scale.

“There are larger market forces driving high-powered computation, high-quality engineering and high-quality battery management in the smartphone market than those in a specialty product,” says Aaron Steinfeld, a research professor at the Robotics Institute at Carnegie Mellon University.

“The reality is, most sighted people don’t know somebody who is blind.” Becker says. “They think the solutions that a blind person needs arc far more expansive, it turns out, they need to be. I think these apps are enabling sighted people to see that blind people just need some simple clues to help them do any number of things in their lives.”

1.What is the first paragraph used for in the text?

A. Showing the main idea.    B. Introducing the topic.

C. Giving one example.    D. Making a conclusion.

2.How does the app Be My Eyes work?

A. By creating a video link between the dibbled and .sighted one.

B. By recognizing which of two cans have tomatoes and cooking.

C. By establishing a high-quality engineering and computation.

D. By flashing the everyday tasks of the technician and volunteers.

3.From the text we can know       .

A. only people with low vision arc registered to use the app

B. slight assistance can help the blind free from some troubles

C. volunteers should be very familiar with high-tech computers

D. Joann Becker thinks it hard to find a bus stop using Be My Eyes

4.What do the 5th and 6th paragraphs mainly mean?

A. Smartphone market has great economic potential.

B. The smartphone becomes a special app.

C. Fine devices have changed the economy.

D. Cost matters when it comes to as5istivc technology.