第17篇 There is one thing. We can’t see it. Sometimes we can hear it and evenfeel ( 感知)it. Without it, all the living things will die. Can you guess what it is? Yes,it is air. However, what’s the air like today? In cities, there are too many people and too many cars on the roads. Thecars send out ( 排放) a lot of bad gases. In cities, there are many chemical factories. Theysend out terrible smoke every day. This kind of smoke is dangerous for ourhealth. Now the air is becoming worse and worse. Every day, we breathe (呼吸) the bad air in and out. This makes us feel sick. So in order to keep us healthy, we have to go to the countryside tobreathe more fresh air. Or we can go up hills to get more fresh air. 根据短文内容,判断正(T)误(F)。 ( )1. Sometimes we can hear air when it blows. ( )2. Some living things don’t need air. ( )3. Many people go to the countryside fortheir holiday because the air there is fresher. ( )4. Too many chemical factories and carscause the bad air. ( )5. The smoke from the chemical factoriesis good for our health.