Why do we need trees? Humans, and actually all other creatures,live on a gas called oxygen. Oxygen is one of the gases found in air and every singlecell inside you needs the oxygen you inhale for energy! Sure, you also need food, but your body couldn’t even make use of the food you eat if you didn’t have that oxygen.When you exhale , you get rid of gases from theair you’re your body cannot use, as well as gases that your body’s cells have produced while at work. This includes a modest amountof carbon dioxide gas that was in the air you breathed as well as the carbondioxide that was made by your body. Now the remarkable thing is that humans cannot breathe pure carbondioxide. Heavy-duty amounts of carbon dioxide are poisonous to them. In fact, that’swhy so many of you have alarms in your homes, similar to smoke alarms, that aremade to go off if they detect the presence of serious amounts of carbondioxide. So, can you image if all humans exhale and our world is filled withnothing but carbon dioxide? You don’t need to worry because we have trees. Throughtheir leaves, trees take in carbon dioxide from the air, use it to make thesugar that is their food, and give off gases, such as oxygen they do not useback through their leaves. Do we need trees? So, the answer is yes, yes, yes. We like trees, but even more importantly,we need trees. We couldn’t afford to lose them! 1. Which of the following is NOT a function of trees? A. Trees take in carbon dioxide from the air through leaves. B. Trees set free oxygen to the air through leaves. C. Trees detect the presence of smoke. D. Trees set free gases they do not use back through their leaves. 2. What does the word “detect” mean in Paragraph 2? A. find B. taste C.touch D. hear 3. Which of the following statements is NOT true according tothepassage? A. Human beings inhale oxygen for energy. B. Human beings make use of the food they eat without the needforoxygen. C. Human beings can’t make use of the food they eat withoutoxygen. D. Human beings exhale carbon dioxide. 4.What can we infer from the passage? A. It’s unnecessary to plant more trees. B. Human beings must breathe pure carbon dioxide. C. Trees play an important role in our life. D. Human beings exhale oxygen. 5. According to the passage, which is the essential for humanbeing? A. oxygen B. food C. carbon dioxide D. water