A poster is any piece of printed paper designed to be attached to a wall or vertical

What is the problem？

A．A poster is missing.

B．A piece of art has not been changed.

C．Rachel sent the wrong poster to a client.

D．Rachel did not give the art vendor clear directions.

【C4】

A．a piece of paper

B．some paper

C．a paper

A．a paper

B．one paper

C．a piece of paper

A．organized geographically information

B．geographical organized information

C．geographically organized information

D．organized geographical information

【B8】

A．a paper

B．one paper

C．a piece of paper

Take a second long piece of paper. Twist the paper once and glue the ends together. Now you have made a Mobius band(带子). For people studying maths, this band is uncommon.

This strange band was first made in the 1800s by a German man namedAugust. Mobius. Mr. Mobius studied maths. He wanted to find a way to show how this band works with maths. Understand it or not, this band has only one surface. You can find this out for yourself.

If you draw a line on the surface of the paper before you twist and glue it, the line is only on one side of the paper. The paper has two surfaces. However, if you draw a line after you make the Mobius band, you can follow the line around all sides of the paper. In other words, the Mobius band must have only one surface.

It is also very interesting to see what happens when you cut the band. If you cut the Mobius band in half once down the line you drew, you do not get two Mobius bands. Instead, after you cut the band, it turns into one large twisted ring. Then, if you cut this ring in half along the middle of the band again, you get two connected(相连的)Mobius bands.

1、What is a Mobius band？()

A、A long piece of paper

B、A paper ring for people to wear

C、A metal ring for music

D、An interesting twisted ring

2、Why didAugust Mobius make this ring？()

A、To help study a maths problem

B、To show it's the same as others

C、To show the only surface of any band

D、To find out how many sides it has

3、How can you change the two surfaces of a long piece of paper into one surface？()

A、Glue the ends of the long piece of paper

B、Cut the two surfaces of the paper into one

C、Draw a line in the middle of the paper

D、Twist the paper once and glue the two ends

4、What do you get if you cut the Mobius band along the middle？()

A、A long piece of paper

B、Two long pieces of paper

C、Two Mobius bands

D、One large twisted ring

5、Which of the following is NOT true？()

A、You can use any long piece of paper to make a Mobius band

B、Any long piece of paper has two surfaces

C、The Mobius band was first made about two hundred years ago

D、You have to draw a line in the middle of the long piece of paper before making a Mobius band

According to Dr. Chin, what makes it possible to track down any paper work is to ______.

A．make all the imperfections of machines deliberate

B．find out the guilty creator of the counterfeit document

C．allow more imperfectly designed printers to be sold

D．mark all the printers in a special and secret way

A．piece, paper

B．pieces, paper

C．pieces, papers

D．piece, papers