Scientists often compare coral reefs to underwater rainforests, yet unlike the leafy plant base of a forest, corals are animals.The soft organs inside the hard parts of corals are naturally transparent and get    1    (they) famously brilliant color from algae(藻类）living inside them.

When corals experience stress from hot temperatures or     2     (pollute),they end their interdependent relationship with this algae,typically forcing them out     3    turning white, though one recent study indicates some corals turn a bright neon color when stressed.Corals are still alive when they bleach(白化），but they're     4     risk-essentially immunocompromised(免疫功能低下）－and many     5     (eventual) starve and die, turning a dark brown.

People first noticed coral bleaching events in the 1980s.The problem worsened in 2016, when an El Nino weather pattern,     6    causes warmer waters in the Pacific Ocean,     7    （mix) with an already unseasonably warm ocean and killed off a third of the corals on the Great Barrier Reef.Since then, roughly half the corals on Australia's famous reefs     8    （die) in following bleaching events, risking an underwater landscape 1,500 miles long.

Scientists around the world are looking for all kinds of ways to protect and maybe even revive corals.One option is     9     (create) more marine protected areas-essentially national parks in the ocean.Scientists say creating marine shelter, where fishing, mining,and recreating are off limits, makes the reefs     10     (healthy), and so much stronger.

China’s Liangzhu Archaeological Site     1    (declare) on the list of World Heritage sites on Saturday by UNESCO’s World Heritage Committee during its 43^rd session in Baku, the capital of Azerbaijan.

The site,     2    is located in Yuhang District in Hangzhou City in China’s eastern Zhejiang Province, showcases the civilization of prehistoric rice agriculture between 3,300 B.C.     3     2,300 B.C. The ruins of ancient Liangzhu city were discovered in 2007, and then large dam sites     4    (surround) the Liangzhu ancient city were unearthed continuously after 2009. It was     5     (official) submitted to UNESCO in 2019, hoping to win     6     (recognize) as a World Cultural Heritage Site. The site     7     (include) archaeological remains and unearthed cultural relics of the Liangzhu Ancient City as well as a wetland that covers     8     area of 908. 89 hectares in a plain river network. It is also found that the Liangzhu ancestors started to use characters about 5 ,000 years ago, 1 ,000 years     9     (early) than previously thought, according to Colin Renfrew, a retired professor of archaeology at the University of Cambridge.

The World Heritage Committee added Liangzhu to the UNESCO list    10     (encourage) better protection of the site, considered to be of “outstanding universal value” to humanity.

4 . Are you facing a situation that looks impossible to fix?

In 1969,the pollution was terrible along the Cuyahoga River Cleveland, Ohio. It    1    (be) unimaginable that it could ever be cleaned up. The river was so polluted that it    2    (actual) caught fire and burned. Now, years later, this river is one of    3    most outstanding（杰出的）examples of environmental cleanup.

But the river wasn’t changed in a few days    4    even a few months. It took years of work     5    (reduce) the industrial pollution and clean the water. Finally, that hard work paid off and now the water in the river is    6    (clean) than ever.

Maybe you are facing an impossible situation. Maybe you have a habit    7    is driving your family crazy. Possibly you drink too much or don’t know how to control your credit card use. When you face such an impossible situation, don’t you want a quick fix and something to change immediately?

While there are    8    (amaze) stories of instant transformation, for most of us the    9    (change) are gradual and require a lot of effort and work, like cleaning up a polluted river. Just be     10    (patience).