题目内容：

    The foldable smartphone was shown for the first time on Wednesday during a Samsung developer’s conference in San Francisco, California. The company first announced plans to build a fully foldable phone five years ago.

The phone is designed to fold open to make the device the size of a small tablet. It can also perform some operations of a tablet. When folded closed, the device looks and works like a normal smartphone. The device will permit users to keep up to three apps open at one time. With normal size smartphones, users have to keep changing between apps.

Justin Dension is Samsung’s senior vice president. He introduced the device to people at the conference. He said it marked a major breakthrough in future smartphone technology. Denison said the design of the foldable device was very complex. One of the biggest difficulties was finding a material that was not only flexible but also strong enough to support repeated folding and unfolding of the device. Denison said Samsung would be ready to start mass production in the coming months.

Technology experts see the new foldable design as a way to get users to buy a new device seen as revolutionary. More people are deciding to hold onto smartphones longer because newly launched models do not offer major improvements and can be very costly. This behavior is one reason for a steady decrease in worldwide smartphone sales over the past year.

It remains to be seen whether foldable phones will become popular quickly. The device is expected to cost more than $1,000. The company has not yet announced when its FlexPai device will be available in America. But it is planning to launch the product in China starting next month, at a price of about $1,300.

1.What did Samsung company do on Wednesday in San Francisco?

A.It announced plans to build a foldable phone.

B.It introduced its foldable phone to the public.

C.It started to sell its foldable phone in America.

D.It held a conference to deal with new challenges.

2.What can we learn about the foldable smartphone?

A.It can run only one app at a time.

B.The material for it was hard to find.

C.It is popular worldwide now.

D.It will take the place of the tablet.

3.What does the underlined part “This behavior” in Paragraph 4 refer to?

A.Recycling their old smartphones.

B.Repairing their old smartphones.

C.Keeping their old smartphones.

D.Replacing their old smartphones.

4.Where does the passage probably come from?

A.A brochure. B.A newspaper.

C.A research paper. D.A shopping guidebook.