Global warming is one of the most serious     1     (problem) humans are facing today. It is caused by human activities, specifically the burning of fossil fuels,     2     produces more carbon dioxide and traps the heat energy into the atmosphere,     3     (cause) the rise of global temperature. Scientists believe global warming may result in severe consequences like the rise of the sea level and the increase of natural disasters.     4    , it is high time that we     5     (take) action to find solutions     6     this problem. As individuals, we should try every means we can think of     7     (reduce) energy at home. Besides, eat locally as a lot of energy     8     (use) to transport food over long distances. Most     9     (important), be     10     educator and help to arouse people’s awareness of energy-saving in your neighborhood to make our world a better place to live in.

Coffee is probably the world's least expensive success power tool. Coffee builds better teams and improves leadership ability. Coffee also    1     (strength) the immune system. Besides, it may even increase     2     (you) lifespan.

    3     (fortunate) we may not be enjoying the benefits or pleasures of coffee too much longer. According to ecologists, there's    4     good chance that in 20 or 30 years, the varieties of coffee we drink today will be extinct. And we'll be drinking either a coffee replacement,     5     some almost-coffee drinks that resemble the coffee we enjoy today.

The problem, of course, is the pace    6     climate change. In the past twenty years, due to climate change, environmental stress     7     (create). It gives rise to the spread of pests and plant diseases,     8     cause damage to the coffee crop and create the possibility of a species-destroying rot.

What can you do? Well, take the time    9     (enjoy) each cup of coffee you drink. Beyond that, stop electing the    10     (politician) who deny climate change.

World Environment Day is held each year on June 5. It is one of the main ways in which the United Nations (UN)     1     (promote) worldwide awareness of the environment. Being the biggest global day     2     (intend) for positive environmental action, it is     3     (wide) celebrated in different countries and also     4     different ways. Activities include street parades, as well as concerts, tree planting, and clean-up campaigns. In many countries, it is a day     5     people from all walks of life come together to ensure a cleaner, greener and brighter outlook for     6     (them) and future generations.

World environment Day     7     (establish) by the United Nations General Assembly in 1972 to mark the opening of the Stockholm Conference on the Human Environment. It is hosted every year by     8     different city and honored with an international exposition through the week of June 5.

The main colors for this event are natural colors     9     (represent) nature, the earth and its natural resources. These colors are often softer     10     (shade) of green, brown and blue. Images of the earth’s features, such as snowy mountains, clean beaches and unpolluted rivers, are used to improve campaigns supporting the day.

How much do you know about the Amazon rainforest? It is without doubt one of the true    1    (wonder) of the world. The Amazon rainforest is of great    2    (important) because it is home to thousands of animals, birds and insects.

The Amazon rainforest is in South America,    3    (cover) most of the Amazon basin of South America. It travels across 9 different countries.    4    (actual), the Amazon rainforest is the    5    (large) rainforest in the world and it has been around for at least 55 million years, Many of the medicines that we use today are from plants in the rainforest.    6    , about 2.7 million acres(英亩) of the rainforest    7    (ruin) each year, which is bad for everyone as forests and trees help to keep our air clean. Scientists think that if climate changes are to increase the world's temperature    8    only 3℃, then 75% of the Amazon rainforest will be destroyed. If all the forests continue to be cut down, 137 rainforest species will be destroyed every single day! That is    9    (frighten). The Amazon rainforest is a very precious place on Earth, and we    10    protect it to make it survive for years to come.

The Xi’an City Wall is the most complete city wall that has survived China’s long history. It     1     (build) originally to protect the city     2     the Tang dynasty and has now been completely restored (修复). It is possible       3     (walk) or bike the entire 14 kilometers.

We accessed the wall through the South Gate. The wall is 12 meters high and from here you can see streams of people moving inside and outside the City Wall.

After     4     (spend) some time looking at all the defensive equipment at the wall, we decided it was time for some action and what     5     (good) than to ride on a piece of history!

We     6     (hire) our bikes from the rental place at the South Gate. My bike was old and shaky     7     did the job. It took us about 3 hours to go all     8     way around the Xi’an City Wall. Supposedly you can do it in two hours, but we stopped at the different gates and     9     (watchtower) to take pictures or just to watch the local people going about their     10     (day) routines.

Whales belong in oceans. However, in September, hundreds of pilot whales     1     (find) stranded (搁浅) on the west coast of Tasmania, Australia, among     2     about 380 died and others remained to be saved. This stranding might have been the country’s largest one on record, local officials said.

Rescue teams pulled the     3     (survive) whales off the sand banks using slings (吊索)     4     some other equipment, so they were fully immersed (沉浸) in water. Once the whales were “re-floated”, they were guided back into deeper waters. Rescuers said they had     5     (successful) sent 50 whales back into the sea.

It is still not fully understood why the whales became stranded. Scientists have a range of     6     (theory). Some assume that the whales were lured (诱惑) to shore by fish and got     7     (lose). Others think that there exists a geomagnetic compass (地磁指南针) in whales’ brains which controls     8     (they) position, and unusual changes in Earth’s magnetic field can affect the whales’ compasses, which can send them     9     the wrong direction. Another explanation suggests one leading whale may have mistakenly led     10     whole group to shore.

Mount Vesuvius is an active volcano located just east of Naples, Italy. It is the only volcano on the continent of Europe that     1     (erupt) in the last one hundred years, though other volcanoes have erupted on islands in the Mediterranean Sea. Vesuvius's earliest     2     (record) eruption is now its most famous. In the year A. D. 79,     3     little or no warning, Vesuvius erupted and completely buried the ancient city of Pompeii. For two days the mountain shot     4     (volcano) material into the air, spreading     5     blanket of ash over the landscape. Pompeii, located seven kilometers from the volcano,     6     (bury) under five meters of ash. The destruction was so complete that it was not until sixteen hundred years later     7     the city was discovered. Evidence of the religion, culture, and everyday life of the Pompeiians, all     8     (leave) behind in the sudden panic of the volcano's catastrophe, are     9     (remarkable) well preserved. And everywhere there are     10     (remind) of its sudden eruption and the shadow of Vesuvius. Even the forms of the citizens remain. Their bodies lie much as they did on the day of their death almost twenty centuries ago.

Wild Chinese sturgeon ( 鲟) are thought to have lived at the same time as dinosaurs and among the first class of protected animals in China. Last week, a wild Chinese sturgeon, which is believed to be the     1     (large) ever found in the past two decades, arrived in Beijing for better treatment. The species is one of the     2     (critical) endangered fish species in China and can be found only in the Yangtze and Pearl rivers.

The Chinese sturgeon “Houfu” ,     3     literally means “good fortune for ever after”, arrived at the Beijing Aquarium on Monday after 22 hours of transport     4     Hubei Province.

When the fish     5     (find) by a fisherman in the Yangtze River Basin, it had been suffering from multiple     6     (injury). It was sent to the Yangtze River Fisheries Research Institute for treatment immediately. As she was so weak, local care takers had difficulty     7     (feed) it. The Yangtze River Fisheries Research Institute decided to move it to Beijing to receive further treatment.

Nicknamed “Aquatic giant pandas” and     8     (list) as a wild creature under state protection, the species has been struggling due to water projects, busy waterway traffic     9     pollution in recent years. The number of Chinese sturgeon living in the wild     10     (fall) sharply to about 50 now from about 1,000 in 1982, according to researchers' estimates.

China's first national park in the Sanjiangyuan area,    1    (cover) a total area of 123,100square kilometers, will open in 2020 on schedule. Sanjiangyuan, the source of the Yangtze, Yellow and Lancang    2    (river), is home to hundreds of species of wild animals. It is also the world's    3    (high) nature reserve with an average altitude of 4,700 meters.

The environment had    4    (previous) worsened due, to climate changes and human activities. Since the trial operation of the park in 2016, the ecological environment of the area has greatly improved. The grassland coverage of the area has risen to 11 percent and grass, output jumped 30percent compared with the last decade.    5    number of wild animals has also seen a rapid increase.

Unlike nature reserves,    6    protect unique species, national parks stress the protection of the entire ecosystem. The foundation of the Sanjiangyuan National Park is of great     7    (significant)to the security of water resources and the protection of rare animals and plant species, and also    8    (mark) the standardization of how natural reserves are managed in China.

Under the national park management, herdsmen and farmers will be turned    9    the central forces of environmental protection at Sanjiangyuan. The work is expected to provide jobs, increase incomes and improve people's motivation    10    (protect) the environment.