READING COMPREHENSION - 1 History of the Earth

The history of the earth stretches over billions of years. In that time period, a lot has changed. Water, wind and ice slowly shape the surface of the earth, constantly moving all around us. Activity just beneath the surface of the earth’s crust creates rapid changes in the shape of the land—that’s where we get volcanoes, landslides and earthquakes. Glaciers, which are huge, very old formations made out of water, earth and ice, can even change the size and shape of the oceans. These major shifts take place over millions of years. We can see the results, but apart from measuring them and seeing where growth or change took place, we can’t observe these changes as they occur. They simply happen too slowly. Erosion is an example of a slow process that changes the surface of the earth. Think of a windy beach, how sand from the beach is carried toward the dunes or, depending on the behaviour of the wind, how the sand from the dunes is carried further down the beach. We can see and feel the sand moving over the land and through the air, but the long-term effects of that movement won’t be visible for years. The earth’s surface is also made up of very slowly moving parts, called tectonic plates. These plates fit like puzzle pieces and make up the outermost layer of the planet. When this layer moves around, it can cause earthquakes and volcanic eruptions. It’s very easy to spot these changes as they’re happening! In fact, we have to be very careful and prepare for them in advance, and take safety measures before and after they occur.

1. What is this passage mainly about?

a) Glaciers and erosion

b) Landslides and earthquakes

c) Changes in the earth

d) Changes in the human body

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