阅读下面的材料，然后根据材料内容回答所提问题。 What do you think is the most common illness? Do you get ill sometimes? We are lucky to live now, because there are lots of medicines to make people better. The most common illness in the world is the cold. It often begins with a sore throat. Then you sneeze and your nose runs. You usually have a headache too. Often you cough later. It's not a very bad illness, but you can feel quite ill. There isn't a cure (治愈) for a cold, but you can take medicines to make you feel better. For instance, aspirin (阿司匹林) can stop your headache. It is good to rest, and to drink a lot of water too. A doctor once said to me, 'With the proper (适当的) medicine, a cold will continue for seven days. With no medicine, it will continue for a whole week!' Where does our medicine come from? A long time ago, people knew that some plants made them feel better. They ate the leaves, the roots, the fruit, or the seeds of plants. For instance, the juice of lemons makes a sore throat feel better. In modern times, scientists have looked at these plants, and found out which chemicals (化学物质) are in them. Many of our medicines today are made from those chemicals. There are some illnesses which we can't cure yet. And nobody has found a cure for old age. But because of modern medicines, many people now live longer than their grandparents. 1. How does a cold often begin? ___________________________________________________ 2. Can aspirin stop a headache? ___________________________________________________ 3. How long does a cold usually continue? ___________________________________________________ 4. What kind of juice makes a sore throat feel better? ___________________________________________________ 5. What are many of our medicines today made from? ___________________________________________________