Traveling can be expensive. But there are some ways to save money when traveling.

Look for city tourism cards. With the card, you can pay less at restaurants and shops. You don't have to wait for a long time at busy attractions. You might even get free tickets to top tourist attractions.

    Don't get the best room. How long will you stay in your room? Will you just be sleeping there? Do you really need a bigger room with a good view? （景色）

Find a hotel outside a city. It can help you save money by choosing a hotel away from big tourist attractions.

    Book(预定) a room with a kitchen. Although some people might not like to cook while on vacation, I don't mind making breakfast in my room. I'd rather eat breakfast and lunch at the hotel and then spend much money on a delicious supper.

    There's much to see under the sea, but you need to remember that light behave differently in water than in air. The objects appear closer to you than they exactly are. You might find yourself reaching out to touch something and completely missing it.

    Objects under water will appear larger than they would on the surface, too. Be careful not to tell any stories about the big fish that got away. That fish might not be so big after all! It's just because sometimes things can seem to be as much as about 33 percent bigger in water!

    What's more, in deeper water, colors just don't seem as bright. In fact, it looks as if some colors are missing. Remember the color of an object results from the wavelength (波长) of light that are reflected (反射) from its surface. And light is taken in as it moves down through the water.

    Swimmers wear wet suits to keep warm underwater. Let's take a bright red, yellow, and blue wet suit as an example. These colors are hard to miss on the surface of water. Watch carefully the changes in color as you descend in the water. The red part now looks almost black because the red light wavelengths, the longest among these three colors, are missing. As you go down deeper, the same thing will happen to the yellow part and in the end to the blue part. Even at a place of about 6 to 9 meters underwater, you will look terrible, like a ghost(鬼怪) ! And you have to wait for your return to the surface to enjoy the bright colors again!

    Technology is everywhere. We see it any place we go and, in fact, almost all of us carry some piece of technology with us every time we leave the house. What I always forget, though, is just how useful and powerful technology can be when we want to help others.

    There is not a single room in my house that does not have some electronic devices （设备）lying around in it. Whenever I am at home, I am almost always using at least one electronic device. If you walked into my living room on any given day, you would find that, first, I have the television on. At the same time, I usually have my laptop resting on my knee, or I will be using my mobile phone. Even when I'm not at home I am always using my phone, and at work or in cafés, I sit down and connect to the local wireless network on my laptop.

    I must say that I waste a lot of time on the computer and the time I spend on it could be much better spent if I were to take up a little online volunteering.

    The technology we carry about everywhere can have a great power to do good for the world and to help others and recently I discovered just how much online volunteering there is to do in the world. From using your language skills to do translations, to developing and managing projects and helping with IT work, there is so much that so many people can do to help people in their own countries and across the world. The United Nations, in fact, has a huge page with "Volunteers Recruited" on its website.

    This work can support the poor and help charities who cannot pay for staff members. Many organizations only require you to work an hour a week﹣some even less. And the support provided by online volunteers can really help make a difference to those in need.

    When you look at the sky at night, the Moon looks bigger than the stars. Actually (实际上), the Moon is much smaller than the stars and the Sun. It's much smaller than the Earth. But the Moon is much closer to us than any star. That is why it looks so big. If you hold a coin close to your eyes, it looks big. If you look at it across the Moon, it looks small.

    The Moon moves around the Earth. It makes one trip in about four weeks. The Moon looks flat to us. But it is a round ball, like the Earth.

    People once thought the Moon had fire (火) on it. They thought the fire made it bright. Now we know the Moon is like a mirror. It gets its light from the Sun.

    Our sunlight comes from the Sun, too. What is the Sun? The Sun is a star. The stars we can see have their own light. There are many big stars we cannot see. Their light has burned out. Others are still bright, but they are so far away that we cannot see them. The Sun looks bigger and much brighter than other stars in Galaxy because it is the nearest of all stars. The Sun and the other stars we see are very hot, but the air around us saves us from the heat of the Sun.

    The Sun gives us light and warmth (温暖). It makes plants grow and turns leaves green. It makes life possible on the Earth. It is a life giving star.

    Many students think that learning a new language is very difficult. But if your brain (大脑) is only the same size as a bird's, you will know how difficult it is to learn English. That is what some birds can do.

Many birds can copy (模仿) the sounds of language. A type of African parrot is very good at doing this. This kind of parrot has grey feathers and people say they are clever.

Every December in London, the National Cage and Aviary Bird Show tries to find the best "talking" bird in the world. One bird named Prudle stood out (突出) among the " talking birds"  by winning this prize every year from 1965 to 1977. In 1958, somebody took Prudle from his nest in Uganda, and then sold it to a woman named Iris Frost. She then took care of him at her home in Seaford, England. Before he died in 1994, aged 35, Prudle knew almost 800 words in English. Prudle was also the oldest bird in the world that lived in a cage.

Another parrot named Puck was tested in 1993. It turned out that Puck knew even more words than Prudle. Puck knew more than 1,700 English words. In the 2003 Guinness Book of World Records, Puck was listed as knowing more words than any other bird in the world.