الكويزات - قراءة المقال
Read the following passage, and then choose the best answer to each of the questions that follow and
mark it on your answer sheet.
B. How many things can you see in the night sky? A lot! On a clear night you might see
the moon, some planets, and thousands of sparkling stars. You can see
even more with a telescope. You might see stars where before you only saw dark
space. You might see that many stars look larger than others. You might see that some
stars that look white are really red or blue. With bigger and bigger telescopes you can
see more and more objects in the sky. And you can see those objects in more and
more details.
2. But scientists believe there are some things in the sky that we will never see. We
won’t see them with the biggest telescope in the world, on the clearest night of the
year. That’s because they’re invisible. They’re the mysterious dead holes black called stars
3. You might find it hard to imagine that stars die. After all, our Sun is a star. Year
after year we see it up in the sky, burning brightly, giving us heat and light. The Sun
certainly doesn’t seem to be getting old or weak. But stars do burnout and die
after billions of years.
4. As the gases of a star burn, they give off light and heat. But when the gas runs out ينفذ
,the star stops burning and begins to die. As the star cools, the outer layers
of the star pull in toward the center.
5. The star squashes into a smaller and a smaller ball. If the star was very small to
begin with, the star ends up as a cold, dark ball called a black dwarf. If the star was
very big, it keeps squashing inward until it’s packed together tighter than
anything in the universe.
6. Imagine if the earth were crushed until it was the size of the tiny marbl.
That’ how this dead star, black hole, is packed. What pulls the star in toward its center
with such power? It’s the same force قوة that pulls you down when you jump—the
force called gravity. A black hole is so tightly packed that its gravity sucks
in everything.---even light. The light from a black hole can never come back to your
eyes. That’s why we see nothing but blackness.
7. So the next time you stare up at the night sky, remember: there’s more in the sky than
meets the eye! Scattered in the silent darkness are black holes---the great mystery of the space.