Mountain climbers around the world dream     1     going up Qomolangma, the highest mountain in the world.     2     many people who have climbed the mountain have left waste material that is harming the environment.

A team of Americans is planning the largest clean-up effort ever on Qomolangma. They will make the     3    (risk) trip of all time up the mountain next month.

The team of eight Americans     4    (guide) by more than twenty Sherpas of Nepal (尼泊尔夏尔巴人). Their goal is     5    (remove) all the rubbish they see. They will spend two months cleaning up the mountain by gathering all kinds of rubbish, among     6     disposable products are a major concern. So the clean-up team will take along     7    (new) developed equipment to collect and treat disposable products. They are expected to remove at least three     8    (ton) of rubbish in large bags.

Team leader Robert Hoffman is making his     9    (four) trip up the mountain. He says he hopes to bring Qomolangma to the condition it was in before the first climb     10    (complete) successfully fifty years ago.

Zou Yi, an environmentalist     1     lives in Beijing, has filmed the a quality near his home using his cellphone since 2013. For almost a decade to now, he     2     (take) more than two million photos to chronicle Beijing major environmental changes. The main purpose of taking these photos is     3     (record) the changes of Beijing’s air quality objectively every day. After two months, Zou Yi selected 64 photos he took and posted     4     (they) online. His move generated extensive discussion.

The fact that China is the first major developing country to combat PM 2.5 may sound unfamiliar to many,     5     most people have heard about the country’s action plan for preventing and controlling air pollution. China has also demonstrated firm resolve in carbon reduction and afforestation. As a result, clear skies and fresh air are returning to major     6     (city).

Days with good air quality accounted     7     87.5 percent of 2021, up 6.3. percentage points from 2015,     8    (make) China the nation with the greatest air-quality improvement worldwide.     9     number of the people who follow the daily air quality photos is     10     (probable) less than 10% of what it used to be. The less attention means that air pollution is not an issue anymore.