Ejercicios Unidad 3

Part I. Read the following text on pollution and its effect on the environment. Then answer the comprehension questions.

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Pollution is the degradation of natural environment by external substances introduced directly or indirectly. Human health, ecosystem quality and aquatic and terrestrial biodiversity may be affected and altered permanently by pollution.

Pollution occurs when ecosystems cannot get rid of substances introduced into the environment. The critical threshold of its ability to naturally eliminate substances is compromised and the balance of the ecosystem is broken.

The sources of pollution are numerous. The identification of these different pollutants and their effects on ecosystems is complex. They can come from natural disasters or the result of human activity, such as oil spills, chemical spills, nuclear accidents ...These can have terrible consequences on people and the planet where they live: destruction of the biodiversity, increased mortality of the human and animal species, destruction of natural habitat, damage caused to the quality of soil, water and air...

Preventing pollution and protecting the environment necessitate the application of the principles of sustainable development. We have to consider satisfying the needs of today without compromizing the ability of future generations to meet their needs. This means that we should remedy existing pollution, but also anticipate and prevent future pollution sources in order to protect the environment and public health. Any environmental damage must be punishable by law, and polluters should pay compensation for the damage caused to the environment.

Principio del formulario

Comprehension

1.      The damage caused by pollution might be irreversible:
a.  True
b.  False 

2.      The ecosystem
a.  can always cope with pollutants
b.  may not always be able to cope with pollution. 

3.      Pollution
a.  is always caused by humans.
b.  may sometimes be caused by natural disasters. 

4.      An ideal solution to prevent pollution would be to
a.  refrain the development of some countries.
b.  continue developmental projects.
c.  Take into consideration the future generations need to live in a healthy environment. 

Parte II. De acuerdo al Titulo y la imagen, ¿cuál cree ud que es el tópico que va a leer?

How a mass spectrometer works

Lee el siguiente texto: 

The basic principle

If something is moving and you subject it to a sideways force, instead of moving in a straight line, it will move in a curve - deflected out of its original path by the sideways force.

Suppose you had a cannonball travelling past you and you wanted to deflect it as it went by you. All you've got is a jet of water from a hose-pipe that you can squirt at it. Frankly, its not going to make a lot of difference! Because the cannonball is so heavy, it will hardly be deflected at all from its original course.

But suppose instead, you tried to deflect a table tennis ball travelling at the same speed as the cannonball using the same jet of water. Because this ball is so light, you will get a huge deflection.

The amount of deflection you will get for a given sideways force depends on the mass of the ball. If you knew the speed of the ball and the size of the force, you could calculate the mass of the ball if you knew what sort of curved path it was deflected through. The less the deflection, the heaviest the ball.

Note: I'm not suggesting that you personally would have to do the calculation, although the maths isn't actually very difficult - certainly no more than A’ level standard! 

You can apply exactly the same principle to atomic sized particles.
Questions.
¿Cuál es la idea general del texto?
¿Qué palabras se repiten?
¿Qué  palabras se parecen en español?