Many people catch a cold in the springtime or fall. It makes us wonder: If scientists can send a man to the moon, why can’t they find a cure (有效疗法) for the common cold? Actually, there are hundreds of kinds cold viruses (病毒) out there. It is hard to know which one you will get, so there isn’t a cure for each one. When a virus attacks (攻击) your body, your body works hard to get rid of (摆脱) it. Blood rushes to your nose and brings congestion (堵塞) with it. You feel terrible because you can’t breathe well, but your body is actually “eating” the virus. Your temperature rises and you get a fever, but the heat of your body is killing the virus. You also have a runny nose (流鼻涕) to stop the virus from getting to your cells (细胞). You may feel unhappy, but actually your body is doing everything it can to kill the cold.