World Ocean Day is an international day that takes place annually on 8 June. It is observed as a     1     (remind) every year of the destruction     2     (cause) by human activities like garbage and waste water treatment and oil leaks. This year the main purpose of the Day is to inform a     3     (wide) public of the impact of human actions     4     the ocean, expecting more people     5     (care) about the worsening situation.

The Day is now celebrated in over 100 countries with hundreds of special events broadcast across the globe. It     6     (mark) in a variety of ways, including launching new campaigns and holding special events, to advance ocean conservation and education.

Young people are an important part. The Day provides them with a platform     7     they can express their concerns and share their ideas. Each year, the Day has a theme for the campaigns and events. For example, in 2016 and 2017 the themes were “Healthy oceans, healthy planet” and “Our oceans, our future”,     8     (respective). “Collective Action for the Ocean” is the theme in 2022,     9     (throw) light on the communities, ideas, and solutions that are working together to protect     10     recover the ocean.

The extinction of the Chinese paddle-fish (白鲟) and wild Yangtze sturgeon (野生长江鲟鱼),     1     (announce) by the international Union for Conservation of Nature (IUCN), started a wave of comments on china’s social media recently, demanding more environmental     2     (protect).

The IUCN’s latest list of threatened species showed that 100% of the world’s remaining 26 sturgeon species are now at risk of extinction, up from 85% in 2009. “The assessment, based on new calculations, shows their decline over the past three generations is     3     (sharp) than previously thought,” the organization said,     4     (add) that the reassessment had also confirmed the extinction of the Chinese paddle-fish. Both the Chinese paddle-fish and the Yangtze sturgeon were common species in the Yangtze river basin,     5     have been troubled by heavy shipping. traffic, overfishing and water pollution.

The Chinese paddle-fish was one of     6     biggest freshwater fish species in the world and could grow up to 7 meters in length. The IUCN ranked it among “    7     (critical) endangered” for the first time in 1996     8     (warn) people of the possibility of its extinction. The Yangtze sturgeon could grow up to 8 meters. Its meat was considered delicious in China.     9     a source of caviar (鱼子酱), it     10     (catch) in great numbers and was purchased at a high price.

PM stands for particulate (微粒的)matter: the term for a mixture of solid particles(粒子) and liquid droplets in the air. Some particles are large or dark enough to be seen by our eyes. Others are so small that they can only     1     (discover) with a microscope.

These particles come in many sizes and     2     (shape) and can be made up of many different chemicals. Some come directly from a source, such as fields or fires. Most particles form     3    the atmosphere as a result of complex reactions of chemicals,     4     are pollutants from power plants, industries and automobiles.

Particulate matter     5    (contain) microscopic particles that are so small that they can be breathed in and make one     6     (serious) ill. Some particles less than 10 micrometers in diameter can get deep into your lungs     7     some may even get into your bloodstream. Of these, particles less than 2.5 micrometers in diameter, also known as PM2.5, create the     8     (great) risk to health.

Fortunately, every day the Air Quality Index (AQI) tells you how clean or     9     (pollute) your outdoor air is, along with associated health effects that may be of concern. The AQI translates air quality data into numbers and colors that help you understand when     10     (take) action to protect your health.

The National Weather Service (NWS) reported that the Tittabawassee River was at least ten     1     (foot) above flood level, and still rising. Under the growing pressure of the water, the Edenville dam and the Sanford dam broke on 19, May, 2020.

The flooding has covered many roads and bridges in Midland County. For     2    ( safe) , so far the Michigan National Guard     3    ( help) in moving around 11,000 people in the nearby towns of Edenville, Sanford, and Midland from their homes.

Midland is home to the Dow Chemical Company,     4     raises other worries. The company has large chemical tanks in Midland which, if    5    (flood),could release(释放)dangerous chemicals into the river.       

For decades, Dow released dangerous chemical pollution into the Tittabawassee River.    6    a result, there is an area farther downstream that is    7    (heavy) polluted. The chemicals there have settled into the mud on the river bottom and in the areas along the river. The area was supposed    8     (clean) up next year. Now there are concerns that the strong flood waters could make the    9    (harm) chemicals come out and release them back into the river. This could cause serious problems, and would make any cleanup far     10    difficult.