Question 1: Read the following passage and answer the questions given below:

Death of Dinosaurs

65 million years ago, dinosaurs suddenly became extinct, together with a large number of other species. But why did it happen?

Many scientists believe that the cause was a large asteroid crashing into the Earth. According to this theory, the asteroid threw huge amounts of dust and water vapour into the atmosphere, blocking out the light of the sun, the vegetation off, and the dinosaurs starved to death.

Evidence for the theory came in 1992 when scientists in Mexico uncovered an underground crater 175 kilometers wide, which turned out to be exactly 65 million years old. The crater was probably caused by an asteroid 10 km in diameter hitting the Earth at thousands of miles an hour, with the force of 70 million one-megaton bombs.

According to David Raup of the University of Chicago, this was just one of many such cases. He says that asteroids have caused more than half of species extinctions sine life on Earth began 600 million years ago. If he is right, it seems likely that Homo sapiens will end its day sin the same way.

NASA to the Rescue

As we can’t predict when a really big asteroid will arrive, is there really any point in worrying about it? NASA thinks there is. It estimates that there are between 1,000 and 4,000 asteroids at least 1 kilometer in diameter which regularly cross Earth’s orbit. If such an asteroid hits the Earth once every 300,000 years, this gives the average person roughly a one in 4,000 chance of being around when it happens. A small risk, maybe, but much bigger than the risk of dying in an air crash, which is one in 20,000.

NASA aims to set up new telescopes and spend the next 25 years working out which large asteroids are likely to arrive within the next century or two. The idea is that once they’ve identified an asteroid heading straight for us, they can move it out of the way by hitting it with powerful nuclear bombs.

1. Why did the dionosaurs starve to death?
   
   
2. What is the evidence given by scientists to support that an asteroid caused mass extinction of plant and animal life?
   
   
3. What does the author say will be the fate of human beings? Why?
   
   
4. NASA thinks that we should be concerned about being hit by an asteroid. Why?
   
   
5. What technology do you think would be sued to prevent an asteroid from hitting the earth?