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Reader's Bank_Level 5_Unit 04                                    Reading Text

A parasite is a tiny animal that lives inside other animals to stay alive. Some parasites can even control their hosts’ brain to achieve their goal. One example is the hairworm. Hairworms go inside crickets and grow inside them. When they are fully grown, they take control of the cricket’s brain. The cricket starts to act strangely. It jumps into water because the hairworm makes it do that. In the water, the hairworm comes out of the cricket’s body. Then it swims around to find another hairworm to mate with. After they mate, the female hairworm lays eggs in the water. But what happens to the crickets? Poor crickets! They become food for fish like trout. So, hairworms not only keep their life cycle going but also help the food chain.

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When people are in a hurry, they eat food like hot dogs and hamburgers. These types of food have a name. Which is the right name, “fast food” or “quick food?” If you chose “fast food,” you are right. The expression “fast food” seems natural, but “quick food” sounds strange to native speakers. However, “quick” sounds right with other words: “a quick meal” or “a quick shower.” Why is that? No one really knows for sure. It is just how native speakers say it. In the English language, many words have their own friends. For example, “heavy” is a friend of “rain,” so these words often go together. Such “word friendships” are called “collocations.” Learning collocations helps you read faster because they allow you to predict what words will come before or after other words.

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Many people think all bacteria are bad. But that is not true! Most bacteria are good for us. Only a few bacteria are bad. When we are born, bacteria start to grow all over our bodies. They are in our mouths, stomachs, intestines, and on our skin. There are as many bacteria in our bodies as human cells. Scientists say there are about 38 trillion bacteria inside us! Bacteria are like guests in our bodies. As hosts, our bodies give them food and a place to live. In return, bacteria help our bodies in many ways. For example, they help us digest food, and they also help us remove waste and fight off bad bacteria and viruses. Without bacteria, our bodies would not work well. Bacteria can live without us, but we cannot survive without them.