Taking away a city’s rubbish is a big job. Every day trucks come into a city to collect it. Most rubbish is made up of things we can’t eat or use. If we kept these things, we would soon have a mountain of rubbish.
In some cities the rubbish is collected and taken outside of city to a dump. Often the city dump is placed where the ground is low or there is a big hole. The kitchen rubbish is broken into small pieces and sent into the sewage system. The sewage system takes away the used wate r from toilets, bathtubs and other places.
To keep mice and flies away, some earth is used to cover the newly dumped rubbish. Later, grass may be planted on the rubbish-filled land. Finally , a house or a school may be built there, and then you’d never know that this had once been an old rubbish dump.
In other cities the rubbish is burnt in special places. The fire burns everything but the metal. Sometimes the metal can be used again in factories where things are made of metal. The food parts of rubbish are put in special piles where they slowly change into something called humus, which looks like black earth. It is rich with kinds of things that feed plants and help make them grow.
【小题1】The underline word “sewage” in the passage means_______

It seems to be strange to you there is a blind spot(点) on the eyes. Here is an interesting experiment that can make something disappear, when one eye is open.

　　Make a card about the size of a postcard and write two English letters L and R on it, L on the left and R on the right. First, hold the card about 80 cm away and you see both the letters. Then close your right eye and look at the letter R only with your left eye. And now, as you move the card slowly towards you, you’ll find the letter L disappearing. But if you move the card nearer to your face, the letter will be seen again. Now do the same experiment with your left eye closed, you’ll find the letter R disappearing.

Why does the letter disappear? It is because there is a blind spot on the eye. When the image of the letter falls on the blind spot, it won’t be seen. That is why either of the letters disappears.

1.The writer of the passage thinks that _____ there is a blind spot on the eye.

A．few people know   B．no one knows      C．most people know   D．all the people know

2.In which order should you do the experiment?

①Hold the card  ②Move the card nearer   ③Close your right eye

④Write two English letters  ⑤Look at the letter R   ⑥Make a card

A．④⑥①②③⑤      B．①③⑥④⑤②      C．⑥①④③②⑤      D．⑥④①③⑤②

3.The passage mainly tells us _______.

A．how to find the blind spot                 B．an interesting experiment

C．where the blind spot is                   D．there is blind spot on the eye