Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions. Floods are common natural disasters that can affect millions of people around the world. They destroy houses and buildings, and carry soil away from valuable farming land. Floods can also contaminate drinking water and lead to diseases. At least once a year the plains around large rivers are flooded. This is due to the amount of water that rivers brings with them, because of heavy rainfall or melting snow in the mountainous regions. Thunderstorms can cause flash floods, in which small rivers can swell quickly and carry up ten times the normal amount of water. Tropical storms and hurricanes also lead to flooding However, floods are not always destructive natural events. Before the Assuan High Dam was built yearly foods in Egypt brought along nutrients and made the land around the Nile very fertile. Question 20. What are NOT the damages caused by floods? Causing unemployment C. Causing diseases B. Destroying houses and buildings D. Polluting drinking water Question 21. How many times are the plains around the large rivers flooded per year? A. Once a year Question 22. What does the word "plain" mean? A. Small rivers Question 23. Are floods always destructive natural events? A. No information B. No, they aren't C. Yes, it does Flat land B. More than once C.Once or more C. Low mountains D. Yes, they are D. Valleys D. None