题目内容：

    Have you ever made a mistake while trying to print from a computer? That paper probably went right into the recycling bin. From there, it is taken to a waste-handling plant to be eventually broken down and remade. But what if you could simply erase your mistake and reuse that paper? It may become available, thanks to a new technology.

It's a new type of rewritable paper that can be used more than 100 times. Words and pictures remain visible on it for at least half a year. This is nearly the first rewritable paper. But the marks on those earlier versions tended to fade away in less than three months.

Luzhuo Chen led the group that made the new rewritable paper. His team was inspired by pens that contain erasable ink. That ink disappears when heated. To make its new rewritable paper, Chen's group switched the ink from the pen to the paper. They covered one side of regular paper with the ink used in those erasable pens. Using a heated pen or printer, they can now write or print on this paper. That warmth makes the ink disappear.

This is the opposite of how writing usually works, where ink is applied to paper. With the new system, the spots where you write become white instead of colored because that heat makes the ink covering the white paper disappear.

Qiang Zhao has a creative mind behind another type of rewritable paper. He thinks Chen's paper is simple and doesn't cost much to make, so it should be easy and fairly inexpensive to produce. However, the paper will need a lot of ink. In large doses（剂量），chemicals in the ink can be bad for the environment and people's health. Zhao would like scientists to develop a safer ink. Still, he thinks this paper will have wide applications.

1.Why does the author raise the questions in the first paragraph?

A.To prove the necessity of recycling paper.

B.To introduce the importance of rewritable paper.

C.To draw readers attention to the new technology.

D.To show the development of paper-making technology.

2.What's the advantage of the new rewritable paper over earlier versions?

A.It can be reused for a lot more times.

B.The costs of producing it are much lower.

C.It can be produced in a much easier way.

D.The contents on it can be more long-lasting.

3.Which of the following reflects Qiang Zhao's opinion on Chen's paper?

A.It still needs improving. B.It's somewhat impractical.

C.It does no harm to its users. D.It's worth promoting right away.

4.What can we know about Luzhuo Chen's new paper from the text?

A.It shows colored words or pictures.

B.It doesn't require ink to write on it.

C.It will replace ordinary writing paper soon.

D.It has no requirement on the writing tool.