Antarctica (南极洲) is the highest, driest and coldest place on Earth. It is also the remotest, a fact which account for its     1     environment. It is widely described as the last     2     on our planet. The cold climate plays a significant role in     3     the continent’s year-round ice fields. Even though Antarctica receives more sunlight than the equator (赤道) , the temperatures are lower because the ice there     4     the heat back into space.

For centuries, Europeans wondered about the     5     of a South-Polar continent, but no one actually knew for certain Antarctica was there until 1820 when European explorers “discovered” it. Since then, men have gone to Antarctica in search of     6     . Testing their abilities, several teams of explorers set out in 1911 to be the first men to stand at the South Pole.

Once completely     7     Antarctica has more recently been playing host to adventurers seeking for excitement, scientists interested in experimenting, and companies looking to     8     this wild area for profit.

Yet, Antarctica’s fragile and complicated eco-system is threatened by its human visitors. Damage to the environment is done as people come looking for resources beneath the ice, or     9     leave their rubbish behind. Currently, countries are working to ensure that the damage to Antarctica’s environment is     10     , and that Antarctica will remain an unspoiled place.

A long red bridge stretches out across water. It runs across the Golden Gate. This is not the     1     to some sacred land, but it is just as     2    . The Golden Gate is where San Francisco Bay     3     the Pacific Ocean, and at night the scene of the bridge     4     up over the water takes your breath away.

Welcome to San Francisco, a place famous for its beautiful parks, hilly streets and lovely beaches. But the bridge is undoubtedly the most well-known symbol of the city. Before its completion in 1937, the bridge was considered impossible to build because of the foggy weather, powerful winds, and     5     ocean currents in the city. However, despite the difficult conditions, the bridge was built in no more than four years. Its total length is nearly 2 kilometers.

San Francisco     6     first on Lonely Planet’s list of the best cities to visit in 2013. According to the world’s largest travel publisher, it came top as a result of its     7     mix.

According to the census, 21 percent of the city’s population was made up of Chinese people. San Francisco’s Chinatown is the largest outside of Asia and the oldest in North America. Two traditional festivals, the Spring Festival and Mid-Autumn Festival, are the biggest events of the year on the city’s     8    .

If yellow cabs are a key part of New York city life, then the cable car is San Francisco’s equivalent. The first cable car came into public service in 1873, and the slow and noisy vehicle has been a symbol of the city ever since. The cable car network was once     9     by a serious earthquake but, luckily, it has now recovered and provides better     10     than the subway.