Days after graduating from Stanford University in 2014, Gayatri Datar set off for Rwanda to pursue     1     unique goal. In Datar’s life plan, what she always wants to do is rid the world of dirt floors, which can make people sick.

“It is easy to find bugs all over the place,” she explains. “Besides, when babies don't have diapers (尿布), they poop and pee (大小便) on the floors, which are really hard    2     (clean).

And they don’t look good, so people hate them.” Yet more than one billion people live on dirt floors,     3    they can’t afford anything better.

Datar’s start-up, Earthenable, sells an earthen floor     4     (make) of locally sourced clay, pebbles, and sand, sealed with special eco-friendly vanish (清漆). It costs about $70 per home, far     5     (little) than concrete.

Earthenable struggled at first.     6     (get) raw materials to rural villages proved costly. Masons (泥瓦匠) had to     7     (train) to install the floors. Quality was unsteady. Datar says:

“Everything that could go wrong did go wrong.”

These days Earthenable is becoming better and better. More than 4, 400 earthen floors have been installed, Datar reports, and customers love them. Earthenable has raised money     8    foundations, the U.S. Agency for International Development, and a     9     (compete) that supports   green   entrepreneurs.   Best   of   all,   Datar   is   working     10     (close)   with   Rwandan government officials who say they really want to remove dirt floors, too.

Over the past half century, using chemical fertilizers     1    (become) very common in farming. Many farmers welcomed     2    (they) as a great way to stop crop disease and     3    (increase) production.     4    (recent), however, scientists have been found that long-term use of these fertilizers can cause damage     5     the land and, even more dangerous to people’s health. With these     6    (discovery), some farmers are beginning to turn to organic farming,     7     is simply farming without using any chemicals. There     8    (be) many different organic farming methods. All of them have     9     same goal: to grow good food and without     10    (damage) the environment or people’s health.

    1    （see）from outer space, Earth is a blue planet, due to the fact that the ocean covers over 70 percent of its surface. According to a new study published in the journal Science, the ocean plays a great role in     2    （slow）down global warming.     3    The New York Times reported, it is “    4    important buffer（缓冲物）”.

The oceans can absorb 93 percent of the heat trapped by the greenhouse gases     5    humans release into the atmosphere. And the other 7 percent     6    （absorb)by the air, land and ice caps, according to the Guardian.

“If the ocean wasn’t absorbing as much heat, the surface of the land would heat up much     7     （fast） than it is right now,” said professor Malin L. Pinsky at Rutgers University in the US. “In fact, the ocean is saving us from rapid warming right now.”

However, the ocean itself, as Discover Magazine noted, is heating up 40 percent faster on average than the United Nations     8    （believe） five years ago. That means if the ocean temperatures increase     9    this speed, the high water temperatures “will kill off marine ecosystems, raise sea     10     (level) and make hurricanes more destructive （破坏性的）”, the Guardian reported.

The International Horticultural Exhibition(世界园艺博览会) 2019 Beijing opened to the public on Monday at the foot of the Great Wall in the Chinese capital’s Yanqing District. Chinese President Xi Jinping declared the     1     (open) of the Beijing expo on Sunday evening.

Sharing with the world the concept and approach of green development, the expo demonstrates Chinese people’s     2       (determine) and confidence in building a beautiful China and a beautiful world.

The Beijing expo       3     (schedule) between April 29 and Oct.7, lasting 162 days.    4     is the second time that China has held such a horticultural expo. The southwestern Chinese city of Kunming held the horticultural expo in 1999.The Beijing expo has drawn participation of about 110         5     (country) and international organizations as well as more than 120 non-official exhibitors. About 2,500     6     (culture) activities, such as parades and performances of world ethnic cultures, will be held throughout the expo,     7     average of 15 for each day.

Over the past 40 years, China’s forest area and forest stock volume have both doubled and its forest coverage rate     8     (increase) to 21.66 percent. The country is home     9       the world’s largest man-made forest in scale, with a preserved area of 69 million hectares. A recent Boston University study     10     (base) on NASA satellite data shows that China alone accounts for 25 percent of the global net increase in leaf area over the last two decades.

Hurricane Katrina has been one of the strongest storms that affect the coast of the United States during the last 100 years. Once a hurricane starts it can     1     ( move ) around by powerful winds. They vary from class 1 to class 5. Hurricane Katrina has been the     2     (bad) storm in the past decade in the US, having reached class 5, which has caused lots of damage.

Some scientists claimed that global warming was     3     ( blame ) for the power of Hurricane Katrina due to the fact that it is warming the oceans. Hurricane Katrina had a strong effect on the US coast. The area     4     ( affect ) is almost the size of the UK. New Orleans suffered from     5     ( severely ) damage after the hurricane. Most of the city was     6     water from flooding, including expressways and bridges. Almost 2 million people     7     ( lose ) their power and had to wait several weeks for it to be restored. It was     8     disaster for the city. Help came from all over the United States. Many people went down to New Orleans to volunteer. Others started charity events to fund the     9     ( reconstruct ) of the city. It was because of all people’s efforts     10     the city began to breathe again.

10 . Hashtag, a pet dog as a gift from a friend to     1     (bright) up my day, saved my life — not once, but twice.

My husband and I had been expecting the exciting     2     (arrive) of him for months before Hashtag came into our home in the winter. I was struggling with depression and suddenly I had something else     3     (require) my attention. I had been overcome by negative thoughts completely, but now I had     4     sense of purpose. I couldn’t give up. Once realizing that, I became     5     (energy). I focused on giving him training and affection, and walking with him. Finally, I got over my depression 18 months later. There’s no doubt     6     Hashtag played an important role in my recovery. Then, last December, we     7     (sleep) deeply when a fire started in our living room. Barking downstairs     8     (unusual), Hashtag woke us up and allowed us     9     (grasp) the seriousness of our situation.

Within moments, we were standing outside. There’s no telling what could have happened     10    Hashtag’s warning. I don’t have the words to describe how grateful I feel for the warning to him.