One day, you open the fridge and find some moldy (发霉的)food. But before you can throw it away, your mother stops you. She doesn't want to waste food. She cuts off the moldy part and eats the rest. Is it safe to do this?

    Mold (霉菌)can grow on almost all kinds of food. Mold is usually green, white, black or grey. Mold makes food soft and changes its color. Moldy food tastes quite bad一一and it's not safe to eat.

    If you find mold in soft food, just throw it away. Soft food, such as bread, tomatoes or hot dogs, usually contains water. This allows mold to easily grow below its surface. Bacteria (细菌)can also grow along with it.

    But it's easy to remove mold from hard food. The mold can't grow very deeply inside this kind of food. According to the BBC, you should cut about 2.5 cm around and below the mold to remove it. It's OK to cut the moldy parts out of hard food and eat the rest. But if the food is completely covered with mold, you should still throw it away.

    Most kinds of mold are bad for us. But some kinds of mold can be used to make food. For example, penicillium (青霉菌)can be used to make many types of cheeses, such as blue cheese. These cheeses are safe to eat--and they're quite delicious as well.

    Thousands of years ago, people didn't know that the Earth moved. They thought the sun really did move across the sky. The Greek god Helios was said to drive the sun across the sky with his chariot (战车). But now, the way people think has changed. Nowadays, it is the sun that drives a "chariot" around the sky.

    What do I mean by this? Well, quite simply, there is now a plane (or "chariot") that is powered by the sun. It has special parts on its wings. These parts absorb (吸收) power from the sun. They absorb so much power that the plane can still fly even at night. In Greek mythology (神话), Helios had to take a break at night. It seems we're finally even more powerful than the gods themselves.

    This plane is called Solar Impulse. It will fly across the US in May. This is very important for the future of the world.

    Why is solar energy (太阳能) important? Well, other kinds of energy are known to cause problems. If you live in China, you've probably noticed the pollution. This is caused by burning coal and gas to make energy. The heat and chemicals created by burning these things give us power. But if we use power from the sun, we don't have to burn anything and there will not be any pollution.

    Solar energy is not entirely ready yet. It needs to be improved. But the best thing about it is that, unlike coal and gas, it doesn't run out. The Solar Impulse plane could pretty much keep flying forever. Of course, the sun's light will eventually run out too one day, but not for another 5 billion years. That's a pretty long flight.

When tea and coffee were first introduced to Europe in the 18th century, people had different ideas about their use. Some said that tea and coffee were harmful to humans and they could cause(引起) people to die.

In Sweden(瑞典), King Gustaf III decided to find out whether or not this was true. It happened that there were two brothers in prison at that time. They were twins and were almost alike in every way. They had both been sentenced to death(判处死刑). The King decided to let them live if one of the men agreed to drink several cups of tea each day and the other several cups of coffee.

Both brothers lived many years without problems of any kind. At last, the brother who had drunk tea every day died at the age of 83, the other died a few years later.

Because of the experiment, tea and coffee got accepted(接受) and became popular as drink in Swe-den, and it is one of the many countries of the world where much tea and coffee is drunk today.

Sometimes it may seem difficult to improve our health. {#blank#}1{#/blank#}

Eat breakfast every morning. 

Research shows that if you eat a meal in the morning, you may not become too fat or eat too much during lunch. Eating breakfast can help people feel better through the day. 

{#blank#}2{#/blank#}

Poor sleep can influence our memory and learning. It can also cause traffic accidents! Studies show that people who don't get enough sleep seem to get into more accidents. So get enough sleep and stay safe!

Take a walk every day. 

Walking is an easy way to exercise. You'd better meet friends for a walk, not for a meal. {#blank#}3{#/blank#}Once you try, you will find that adding a walk into your daily life is very easy. 

Join social groups. 

Social groups can provide support. They might include sports teams, art or music groups. The people in the group can offer advice and help each other in difficult times. {#blank#}4{#/blank#} An active mind is a healthy mind!

Have a hobby. 

A hobby could be running, reading or making something with your hands. Hobbies help people to relax and rest. {#blank#}5{#/blank#}

A．Get up early. 

B．Get enough sleep. 

C．Hobbies bring us happiness as well. 

D．Also, being in a group keeps your mind busy. 

E．If so, the following healthy habits may help you. 

F．As you walk, you will see the beautiful world around you. 

We do eye exercises. We wear sunglasses (太阳镜). We do lots of things to protect our eyes. But we usually forget another important part of our body—the ears. 

Ears help us hear the world {#blank#}1{#/blank#}. Once this happens, it's hard to get your hearing back. So how can we protect our ear ■■■take a look together. {#blank#}2{#/blank#}

Dry your ears with a towel (毛巾) after swimming or taking a bath. If you feel water in your ear, shake your head a little bit. This can help you get the water out of your ear. {#blank#}3{#/blank#}During the winter, protect your ears with a hat or a scarf.

Keep your ears clean

Usually, our ears clean themselves. The earwax (耳屎) builds up, dries out, and then comes out of the ear along with some dirt (污垢).

Don't clean your ears with anything sharp (尖锐的), or it can make the earwax go too deep into your ears and hurt them. {#blank#}4{#/blank#}.

How to use headphones (耳机)

Don't listen to loud music on your headphones for a long time. Follow the 60:60 rule: listen to music at 60 percent of your headphones' maximum volume (最大音量) for no more than 60 minutes a day.

{#blank#}5{#/blank#}. They do a better job of stopping outside noise so you can. listen at a lower volume.

Choose five sentences out of the six in the box to complete the passage. Each choice should be used only once

A. How to use your ears.

B. Keep your ears dry and warm.

C. Over—the—ear headphones are better than in—ear ones.

D. But if your ears start to hurt, you can go to a doctor for help.

E. But many things, such as loud noises, can cause hearing loss (听力丧失).

F. Also, when the sun is shining, wear some sunscreen (防晒霜) on your ears.

①"Hey, want to do something great with old soft drink cans?""Sure, let's use them to go to the moon!"

②I know that sounds crazy. After all, you can't build an Apollo rocket from old soda cans. However, if you recycle enough cans, you can save as much energy as there is inside a real Apollo rocket. Enough power to reach the Moon!

③Soft drink cans are made of aluminum(铝). Making this metal requires a lot of energy. Aluminum begins as bauxite ore(铝土矿). The ore must be extracted(采掘), crushed(粉碎), and smelted(炼取). Producing soft drink cans needs about 1% of all the electricity used in the USA. Americans use more than 100 billion soft drink cans every year!

④Can we do better? Yes, we can, by recycling. While it takes lots of energy to produce new aluminum, it takes very little energy to turn old aluminum into new products. The metal is simply shredded(撕碎), melted(融化) and recast(再铸) into blocks(大块). By recycling, we can produce 20 soft drink cans using the same energy it would take to make just 1 new can.

⑤Nationwide(在全国), about 100,000 cans get recycled every minute. To be exact, in 90 minutes, the energy saved by rècycling is: E gained by recycling=2000,000 joules(焦耳, 能量单位)*9000, 000cans=18 trillion.

⑥That's a lot of energy. What can we do with that much energy? Can we reach the moon? It does sound crazy. But do you know how much energy do we need to send a rocket to the moon?

15.7 trillion.

⑦Now, compare two values for energy. See? The energy saved by recycling old soft drink cans is more than enough energy to send a rocket to the Moon. And we didn't even need a whole year of nationwide recycling—— just 90 minutes of recycling did it!

⑧Isn't it a fascinating way to think about recycling? Yet each time you save an empty soft drink can, it's almost like you' re helping to send a racket.