Birdwatching is becoming more and more popular in many parts of the world.

Birdwatchers enjoy looking for and listening to different kinds of birds. To watch birds, all you need is a pair of binoculars, a field guide and love for birds.

If you are just starting birdwatching, buy one of the cheaper pairs of binoculars. You can choose better ones when your needs and skills grow. A field guide helps you learn about the birds’ appearances, calls and habits before birdwatching.

When you are ready, it’s best to go to the wild with someone who is more experienced. You can join a birdwatching group to learn about some beginning skills. A local bird club is ideal.

Start birdwatching in the morning, when birds are searching for food. Most of the time, you will hear bird calls from all around you, but will not see any birds easily. Look for movement in trees, and bring your binoculars to your eyes.

The most important work for a birdwatcher is to identify the birds he/she sees. A bird’s shape, size, colour and habits can help a birdwatcher identify it. When you identify a bird, don’t forget to take notes about it on your notebook.

To find more and different birds, you may wish to plan trips to birds' different living areas: forests, lakes, rivers, wetlands, etc.

When watching the birds, you should always keep in mind: respect wildlife and protect its living areas.

Many of us have this experience: we lie down in a bed, not our own, maybe at a friend’s house or in a hotel room, and find it difficult or impossible to fall asleep. Is it because the bed is uncomfortable? Maybe, but perhaps there can be other reasons.

According to a new study in Current Biology, an important reason is what the scientists call “first night effect (效应)”. They believe that it is because one side of the brains is more active. It forces us to stay awake on the first night in a new environment. The effect acts as a “night watch” to protect us from potential (潜在的) danger.

For the study, 35 young volunteers were asked to sleep in a sleep lab for several days. At the same time, researchers watched their brain activities.

According to the researchers, on their first night, the left brains were more active than the right brains and people had a hard time sleeping. However, left-brain activity reduced (减少) as days went by, falling even to the point of complete peace. In this process, the volunteers got an increasingly better sleep experience.

“At some level, the brain is continuing to analyze things, even though you can’t realize it.” US professor Jerome Siegel told Smith Sonian Magazine, “If something unusual happens—if a door opens or you hear a key in a lock—you can be alert (警觉的).” It works to protect us in a dangerous environment. More surprisingly, this is similar to the way some animals sleep. Whales, dolphins, and many birds can sleep with half of their brain while the other half stays awake, with its one eye staying open.

If you have ever had what you think is “first night effect”, researchers suggest that you bring your own pillow (枕头) or sleep in a room similar to your bedroom next time you sleep away from home.

As space science develops, man has learned more and more about space. Space is not only amazing but also dangerous. While working in space, spacemen are facing danger.

Scientists have found out that radiation (辐射) is the greatest danger to spacemen in space. When spacemen are working in space, they are in danger of radiation from the sun and other stars, which is bad for their health. The damage done by radiation won’t be discovered until their children or even grandchildren are born. Some special medicine may work a little, but no really helpful medicine has been found.

Space junk is also thought to be a great danger to spacemen. It’s reported that there are 9,000 man-made things flying in space. About 30% of these are man-made satellites (卫星), 10% are spaceships, and the rest are space junk. An explosion (爆炸) in 1999 made a cloud of 300,000 fragments , each at least 4mm in size, and even a small piece of these knocked against a spaceship window and did some damage. Scientists are watching and reporting any possible danger all the time. They are working on helpful ways to deal with space junk.

Although space is really dangerous, it interests everyone on the earth. In the near future, it may become usual for people to spend a few days in a space hotel. We may even choose to leave the earth and live in space in a few years. So we should care for space and do something to help improve the space environment.