Men have always wanted to fly like birds. Birds can fly easily because they are light, but men's bodies are heavier.

    Men first went up into the air in balloons. These were big bags, and they were filled with gas. Hydrogen (氢气) is a useful gas for balloons. It is lighter than air. Helium is also lighter than air, but it costs a lot of money. So balloons are usually filled with hydrogen.

Balloons have to fly with the wind as they have no engines (发动机) to drive them. Later, men made airships. They are balloons with engines. They are also filled with hydrogen.

    Aircrafts (飞机) with wings now take people across the world. Powerful engines drive these machines across the sky. Some of the engines are like the engines of cars, but they are more powerful.

    There is another kind of engine, we call it the jet (喷射) engine. An English engineer invented the jet engine. At the same time, Germans were also building a jet engine. In May 1941, the English engineer's new engine was fixed in an aircraft, and the aircraft flew quite well.

    Jet engines are very powerful. Usually two to four are enough for an airplane, but some big aircraft need six. Anyone in a moving jet plane can feel the power of the engines. Jet planes can travel faster than sound. As a flying jet plane leaves its noise behind, we do not hear it until it has gone.

    You may know the English letters A, B and C, but do you know there are people called “ABC”? You may like eating bananas, but do you know there are people called “banana persons”? If you don't know, I will tell you about it. They are some Chinese people like you and me, but they aren't in China. Why do people call them like that?

    If we call somebody an ABC person, we mean he or she is a Chinese but was born (出生) in America. Sometimes, people also call them “banana persons”. A banana is yellow outside and white inside. So if somebody is a “banana person”, he or she is “white” inside and “yellow” outside. By saying that, we mean he or she has yellow skin(皮肤) but does things in an American way. “Banana persons” were born in America and they live in America for a long time, so they think like Americans and do things like Americans. However, these people still have Chinese blood(血统). Their parents, grandparents or even great-grandparents are from China. They all have black eyes and black hair, so they look like us, Chinese people.

    There are many famous “banana persons” in America. They do very well in America and they are really great in their own fields.

    Canada is the second largest country in the world. It is over 7，000 kilometers from the 1 coast（海岸）to the east. It 2 six time zones. 3 it is 9 a. m. in Vancouver on the west coast，it is 1：30 p.m. in St John's on the east coast.

    English and French 4 the two main languages in Canada. About 60 percent of 5 people speak English， and about 25 percent speak French. More 6 70 percent of its population live in cities near the US border（边境）.

    Ottawa is the capital. Every year millions of tourists go there to7 museums and take part in the cultural（文化的）activities. Toronto is the largest city of the country 8 about 2. 5 million people. Montreal is 9 second biggest French-speaking city in the world.

    The maple leaf is the national symbol of Canada. The Canadian flag has a red maple leaf on a red 10 white background.