Long, long ago, people made fires from lightening (闪电). But they had to keep the fire burning, for they couldn’t start it again if there was no lightening. Later, they found out hitting two pieces of stone together could make a spark (火花). The spark could fire dry leaves. In this way they could make fire again if it went out. Then people also learned to make a fire by rubbing (摩擦). They made a hole in a piece of wood and put a smaller stick into the hole. They turned the stick again and again. After a few minutes they got a fire.

Years went by, people learned other ways to make a fire. Sometimes they used the heat from the sun. They held a piece of glass in the right way and made a piece of paper on fire.

About two centuries ago, people began to make matches. Matches brought people a quick and easy way to make fire. Today matches are still being used, but people have more new ways to make fire. One of them is to use an electric fire starter. Of course an electric fire starter is much more expensive than a box of matches. But it is very useful.

Round eyes, round head, round ears, round body! What is this lovely little animal?

He looks like a bear. But he is not a bear. He’s a KOALA.

People in Australia love koala and take care of them. They have set up places for them to live safely. No one can kill them for their pretty fur （毛片）. When a koala is born, he has no fur. And he is not as big as your little toe （脚趾）! The mother koala has a pocket in the front of her body. The baby goes into this warm pocket. There he stays for six months.

When the baby leaves the pocket, he has much fur. And he is about as big as your shoe. He climbs to his mother’s back. He rides there while she teaches him how to find food. Mrs. Koala is a loving mother. She takes good care of her baby. But when he is bad, she beats him! The baby cries just as a small child does. If he keeps on crying, his mother beats him again. When he stops crying, she takes him in her arms. And then they both go to sleep for a while.

The koala could not live without a special kind of tree. The tree gives him both his home and his food. For most of the day the koala sleeps in the tree.

At night the koala looks for food. He may go miles to find it. He likes only the bark（树皮） and the leaves of the tree. He eats nothing else. And he eats more than two pounds each night!

How lovely the koalas really are!

We touch our faces all the time, and it had never seemed to be a big problem—until COVID-19 arrived. Touching our faces—the “T-zone” of our eyes, nose and mouth—can mean giving ourselves this virus.

This is why some organizations have suggested that we should avoid touching our faces. William Sawyer, from Henry the Hand, told The Washington Post, “Just stop this simple behavior, and that would be better than any vaccine （疫苗） ever created.”

However, stopping this “simple” behavior might be harder than you think because we are used to it.

Some face-touching is an automatic reaction—like when there is an itch(痒) on your nose, you'll touch it again and again without thinking. A 2014 study found that touching your face also helps you to have less stress. For example, it's possible for you to do it when you feel embarrassed. According to Dacher Keltner, a psychologist at the University of California Berkeley, US, this action may also have a social use: When you are talking to someone, for example, touching your face means you want to talk about another thing.

Besides, it's very hard to change this face-touching “because you don't even know you're doing it”, said Sawyer.

But you're not alone. In a 2015 study, it was found that a group of medical students touched their faces about 23 times an hour-with 44 percent of the touches in the “T-zones”. That was very surprising because medical students should know better.

Since it's so hard to shake the habit, maybe the easiest way is to wash our hands more often. This way, we can be sure that our hands are safe from COVID-19.