【推荐1】A

Water had also appeared on other planets like Mars but,     1     the earth, it     2     later. It was not immediately obvious that water was to be     3     to the development of life.     4     many scientists believe is that the continued presence of water allowed the earth to dissolve     5     gases and acids into the oceans and seas.

B

Some people have the idea that you can cross Canada in less than five days, but they forget     6     Canada is 5,500 kilometres from coast to coast. Here in Vancouver, you’re in Canada’s warmest part. People say it is Canada’s most beautiful city,     7     by mountains and the Pacific Ocean. Skiing in the Rocky mountains and sailing in the harbor make Vancouver one of Canada’s most popular cities     8     in. Its population is increasing rapidly. The coast north of Vancouver has some of the oldest and most beautiful forests in the world. It is so wet there that the trees are     9     tall, some     10     over 90 metres.

Last week, I attended a lecture on lost     1    (文明). It was about Pompeii and Loulan, both of which were busy and w    2    about 2,000 years ago. F    3    in the 8th century, Pompeii was d    4    by a volcano, a natural     5    (灾难) that buried the whole city alive.    6    (与……不同) Pompeii, Loulan disappeared mainly because of the damage humans did to the environment. Once a     7    (商业的) city on the famous Silk Road between the East and the West, Loulan was covered with huge trees. But the trees were cut down and the city was     8     (逐渐地) covered over by sand. T    9     we ought to a    10    great importance to environment protection.

Imagine mountains wrapped in silver water, shining in the spring sun. Summer s    1     the mountains turn bright green with growing rice. During autumn, these same mountains are gold, and in winter they are covered in s    2     of white frost. These are the colours of the Longji Rice Terraces.

These terraces were built by the local Zhuang and Yao people. R    3     as far as the eye can see, these terraces cover tall mountains, often from the bottom to the very top.

So why did these people go     4     so much trouble to turn the entire mountains into terraces? Firstly, building the terraces meant that they could increase the areas in which they could grow rice. Secondly, the     5     terraces catch the rainwater and prevent the soil from being washed away.

But perhaps what is most significant is the way in which people have worked in     6     with nature to make these terraces and grow rice. The terraces are cleverly designed, with hundreds of waterways that     7     with each other. During the rainy season, it is along these waterways that rainwater moves down the mountains and into the terraces. The sun heats the water     8     turns it into vapour. This forms clouds from which rain falls down onto the mountain terraces once again.

Although modern technology could help produce more crops, these terraces still mean a lot to the local people for     9     traditions hold much value. Today, the Longji Rice Terraces attract thousands of visitors who come to admire this great wonder c    10     by people and nature working together.