Debates       1     the subject of carbon capture have been going on recently. Scientists, especially engineers and geologists, have strongly criticized green groups who claimed that carbon capture and storage (CCS) schemes are costly mistakes.

The scientists insisted that such schemes     2     (be) vital weapons in the battle against global heating. They also warned that failure to set up ways to trap and store carbon would make it     3     (possible) to meet the emissions target by 2050. “CCS is going to be the only effective way in the short term     4    (prevent) our steel industry, cement manufacture and many other processes from continuing to pour emissions into the atmosphere,” said Professor Stuart Haszeldine, of Edinburgh University. “    5    we are to have any hope of keeping global temperature increases down below 2 degrees Celsius, we desperately need to develop ways to capture and store carbon dioxide.”

Green groups claimed CCS would not make “a meaningful contribution to 2050 climate targets”. They said CCS was not reliable to decarbonize the energy system and that CCS had     6     history of over-promising and under-delivering. Instead, they urged the construction of more renewable energy plants    7     (give) priority.

But the claims     8     (dismiss) by engineers and geologists. “These claims are quite unfair,” said Michael Stephenson, director at the British Geological Survey.

A government spokesman for the Department of Energy and Climate Change said, “We are committed to meeting our climate change targets in a way     9     is affordable and provides secure energy to families and businesses. We are considering the role that CCS could play in decarbonization of the UK. But we also need to take government     10     (spend) into account. CCS had better come down in cost.”

Home to the headwaters of the Yangtze, Yellow and Lancang rivers, the Sanjiangyuan area on the Qinghai-Tibet Plateau (高原), is known as “China’s water tower.” It is a     1    (whole) significant plateau wetland ecosystem and serves as     2     unique ecological defense for the country.

Decades ago, serious environmental degradation (恶化) in Sanjiangyuan,     3     was caused by climate change and human activities, resulted in a large number of lakes drying out and wildlife numbers falling sharply. In 2016, the pilot program for the Sanjiangyuan National Park management system     4    (launch). Through painstaking development and innovation, efforts have been made     5    (turn) the park into a symbol of the progress of China’s ecological civilization.

Over the past decade, the ecological environment of the Qinghai-Tibet Plateau     6    (experience) enormous changes. Water conservation in the area has risen     7     11 percent every year, reaching 75 percent mark compared with 64 percent 10 years ago.

The     8    (establish) of the national park has enabled local residents to change from exploiting (开发) nature to becoming its protectors, some of them     9    (serve) as tour guides for visitors from home and abroad.

Today, as people wander on the vast land of Sanjiangyuan, looking at the expansive mountains, glaciers, lakes and pastures,     10     catching sight of wild animals and birds, they cannot help be impressed by the vastness and beauty of nature and its biodiversity (生物多样性).

Polar bears live in a special environment that is too cold for most animals. For much of the year, they live and hunt on the     1     (freeze) Arctic sea ice. Nature has prepared them for the cold conditions but nothing has prepared them for the danger     2     threatens (威胁) their only home.

The polar bears’ world is melting. Polar bears     3     (suffer) in a warmer world are in danger. Studies show that the polar ice     4     (decrease) by 9.8% every 10 years since 1979. At present, about 20,000 to 25,000 polar bears live in the Arctic. Polar bears depend on the sea ice for their     5     (survive). “The sea ice is more than just the platform that the bears walk     6    ,” says Andrew Derocher, who studies North American polar bear populations. “Without     7    , they can’t exist.”

Some melting and refreezing of the sea ice is     8     (nature). But in a warmer world, these cycles speed up, and bears have less time to hunt.     9     (normal), they have three months in the spring when they gain more weight and the extra fat is used later, when the bears are not actively hunting.     10     it is important to protect the environment and keep the ecological balance.