I've always loved the ocean. In the    1     (seven) grade,I started volunteering at the Monterey Bay Aquarium in California. I was upset to learn that many sea animals eat plastic garbage,     2     (think)it is food.

I decided to do something     3     (educate) people about this problem. I held presentations at schools to teach kids about plastic waste. I wanted to reach businesses too. I decided that if I learned of a company    4     used a lot of plastic, I'd send it an email urging it to cut back.

One day, I saw a commercial for a health-care company. People in the ad were using plastic straws （吸管）.   I found the contact information of the company    5     emailed its president. I told him how     6     (harm) plastic could be to the environment and asked him to consider using more eco-friendly options. I was so    7     (excite) when he wrote back to me.He said he would make sure that the company cut its use of plastic straws in half.

I kept going. Whenever I heard of businesses using plastic, I'd send an email. One of the biggest companies I wrote to     8     (be) Alaska Airlines Paris. A company     9     (represent) wrote back and told me the airline was switching over     10     plastic to paper cups on all of its 1,200 daily flights.

There     1    (be) a dramatic rise in the number of extreme weather events over the past 20 years,    2    (cause) largely by rising global temperatures,according to a new report from the United Nations. From 2000 to 2019, there were 7,348 major natural disasters around the world,    3    (result) in USD 2,970 billion in economic loss．Much of this increase can be due to climate change. The findings show a critical need     4     (invest) in disaster prevention.

Why do we dream？Scientists aren't completely sure,and they have diverse    1     (idea)．Dreams might be a side effect of memory making.When you sleep,your brain sorts through everything     2     happened during the day，trying to link new experiences to old memories.As it     3     (connect) things，your brain turns them into a story,and you get a dream．

It doesn’t impress like George Washington’s plantation on the Potomac, but Lincoln’s home in downtown Springfield, Illinois,     1     （prove）irresistible to visitors since it opened to the public. Beautifully restored（修复）to its 1860 appearance, the house was Abraham and Mary Lincoln’s home for 17 years. In 1844 they bought it     2     $1,200 and some land from Charles Dresser, who performed their     3     （marry）ceremony in 1842.

When the house was built, it was much     4     （small）than it is today. Mary’s niece wrote, “The little home     5     （paint）white.” It was sweet and fresh. Mary loved it. She was extremely pretty, and her house was a reflection of     6     （she）, everything in good taste and in perfect order.

Although Mary loved flowers,     7     she nor her husband was known as a gardener. A long- time neighbor said they never planted trees and only kept a garden for one year. Mary’s sister, Frances Todd Wallace, often came over     8     （plant）flowers in the front yard.

    9     Lincolns enlarged the house to a full two-story in 1856 to meet the needs of their growing family. Three of the four Lincoln sons were born here. After Lincoln was elected President of the US in 1861, they rented the house and     10     （sell）most of their furniture.

The Xi’an City Wall is the most complete city wall that has survived China’s long history. It     1     (build) originally to protect the city     2     the Tang dynasty and has now been completely restored (修复). It is possible       3     (walk) or bike the entire 14 kilometers.

We accessed the wall through the South Gate. The wall is 12 meters high and from here you can see streams of people moving inside and outside the City Wall.

After     4     (spend) some time looking at all the defensive equipment at the wall, we decided it was time for some action and what     5     (good) than to ride on a piece of history!

We     6     (hire) our bikes from the rental place at the South Gate. My bike was old and shaky     7     did the job. It took us about 3 hours to go all     8     way around the Xi’an City Wall. Supposedly you can do it in two hours, but we stopped at the different gates and     9     (watchtower) to take pictures or just to watch the local people going about their     10     (day) routines.

Going to Mount Huangshan reminds me of the popular Beatles’ song “The Long and Winding Road”.     1     is so breathtaking about the experience is the out-of-this-world scenes. The rolling sea of clouds you see once you are at the top will remind you how tiny we     2     (human) are.

The hot spring at the foot of the mountain is something you must try after the climb. It will     3    (undoubted) help you get refreshed! The amazing thing about the spring is that the colder the temperature gets, the     4     (hot) the spring! Strange, isn’t it? But that’s how nature is — always leaving us     5     (astonish).

What comes next is the endless series of steps. You can’t help wondering how hard it     6     (be) for the people then to put all those rocks into place. Though it is the only unnatural thing on your way up the mountain, still it highlights the whole adventure     7    offers a place where you can sit down to rest your     8     (ache) legs.

As the song goes, this long and winding road “will never disappear”, and it will always stick in the visitor’s memory. It sure does in     9     (I). While you’re in China, Mount Huangshan is     10     must to visit!

Ecotourism is commonly regarded as low impact (影响) travel to undisturbed places. It is different from traditional tourism because it allows the traveler to become     1     (educate) about the areas - both in terms of geographical conditions and cultural characteristics, and often provides money for conservation and benefits the     2    (develop) of the local areas.

Ecotourism has     3    (it) origin with the environmental movement of the 1970s. It was not widely accepted as a travel concept     4     the late 1980s. During that time, increasing environmental awareness made it desirable.

Due to     5     growing popularity of environmentally-related and adventure travel, various types     6     trips are now being classified as ecotourism. Actually, a true eco-friendly trip must meet the following principles:

·Minimize the impact of     7    (visit) the place.

·Build respect for and awareness of the environment and cultural practices.

·Provide     8    (finance) aid and other benefits for local peoples.

·Make sure that the tourism provides experiences for both the visitors and the hosts.

Komodo National Park, officially recognized in 1980, is popular for ecotourism because of its unique biodiversity.    9    (activity) there range from whale watching to hiking (远足) and accommodations aim     10    (have) a low impact on the natural environment.