题目内容：

If you are ever planning to buy a telescope and want to get yourself involved in astronomy it is always a good idea to know a bit of the sky.Get acquainted with a few constellations(星座) so that it will be easier for you to spot the constellations when you are using your telescope.

It’s a good idea to buy a few magazines on astronomy to help you to get familiar with the constellations in the sky and also read a few reviews on the different types of telescopes in the market.This will help you gather all the information that is out there regarding telescopes and what people have to say about them.

It’s advisable to go in for a pair of binoculars(双筒望远镜) before you buy your first telescope so that you can get used to spotting constellations before your view of the sky is narrowed down.This will also help you know if you really want to get involved in astronomy.Many people buy a costly telescope and then discover that they’re not actually interested in astronomy.

Experience has no substitute，and there certainly is nothing better than using different telescopes before you buy one.This will help you to get the feel of all the types of telescopes and you will know which one is easier for you to use.A large aperture(光圈) refractor(折射) may give you an excellent image but you may not be able to keep a steady hand while using it resulting in a blurry image.

There are three types of telescopes that are available in the market.If you want a more elegant looking telescope you can always choose to buy a fine brass telescope.It’s good to become acquainted with each type before going for the plunge of a first telescope.The first type of telescope is the refractor telescope，which uses lenses to gather light to a focus at the eye piece.The use of lenses helps the telescope have a superior image.A refracting telescope is not as portable as the other two types of telescopes and so you will have to buy one with a small aperture.

The second type of telescope is the Reflector.Made by Sir Isaac Newton，this telescope functions by focusing the light back at the front of the tube，which is where the eyepiece sits，by using parabolic(抛物线的) mirrors and another smaller mirror to deflect the light.There is no added color in the image caused by refraction of light since this telescope does not use lenses.These are the cheapest of all telescopes and are more portable than refractors.

1.According to the text，a telescope is intended to be bought for ________.

A．getting experience

B．watching stars

C．studying the climate

D．learning about a bit of the sky

2.What can we learn from Paragraph 2?

A．One must know something about astronomy and telescopes.

B．One can’t buy a telescope without buying several astronomy magazines.

C．One should check the telescopes in the market and try to find a better one.

D．One must be familiar with new information of astronomy and space instruments.

3.Why does the author advise buying a pair of binoculars first?

A．The telescope is too expensive.

B．The binoculars are easier to use.

C．You may gain plenty of experience in astronomy.

D．Your view will be narrow by using a pair of binoculars.

4.What do we know about the refracting telescope?

A．It looks very elegant.

B．It refracts light by an eye piece.

C．It has clear images without any lenses.

D．It is not convenient to take along for its size.