阅读下面材料，从每题所给的A、B、C、D四个选项中选出最佳选项。

Dear Edward,   

    How are you doing? I just visited Machu Picchu in Peru today. I've never seen such a great place before. This place is so amazing that I want to share my feelings with you.

When I first got to Machu Picchu, I felt like I was walking in the sky. Even the clouds were just under my feet. Do you know how high Machu Picchu is? I was surprised that it was at about 2,500m. How could people build a city on such a high mountain? It must have been very difficult to move stones there.

Before the Europeans arrived, the Incas (印加人) were the last and the most modern society in the Andes (安第斯山). The Incas were afraid that the Spanish would find them, so they built Machu Picchu on an Andes plain (平地) as a secret city in the 14th or 15th century. As a result, the Spanish never found Machu Picchu.

An American explorer discovered Machu Picchu in 1911. For a long time before that, nobody even knew Machu Picchu was there. After Machu Picchu was found, it was called "The Lost City of the Incas". It is still a mystery why and how Machu Picchu was left and forgotten by everyone.

I just had a wonderful day. Especially, I will never forget the "goodbye boy" who was a local boy dressed in traditional Inca clothes. When we went down the mountain by bus, the boy waved goodbye to us until we were out of sight (视线). He shouted some words at us too, and I guess, it meant, "Goodbye, come back again soon!" Why don't you visit Machu Picchu someday? I am sure you will love this place as much as I do.

                                                                                                                                                                      Yours truly,

                                                                                                                                                                          Lynn

    Today, roller-skating is easy and fun. But a long time ago, it wasn't easy at all. Before 1750, no one had any ideas of roller-skating. That changed because of a man named Joseph Merlin. He liked to make things and play the violin in his free time. He was a man of ideas and dreams. People called him a dreamer.

    One day Merlin was invited to a party. He was very pleased and a little excited. As the day of the party came near, Merlin began to think how to make an amazing entrance at the party. He had an idea. He thought everyone at the party would show much interest if he could skate into the room. He tried different ways to make himself roll. Finally, he decided to put two wheels under each shoe. These were the first roller skates. Merlin was very proud of his invention and dreamed of arriving at the party on wheels while playing the violin.

    On the night of the party Merlin rolled into the room playing his violin. Everyone was very surprised to see him. There was just one problem: Merlin had no way to stop his roller skates. He rolled on and on. Suddenly he ran into a mirror that was hanging on the wall. The mirror fell down, breaking into pieces. Merlin's idea was so good that nobody forgot his special entrance for a long time. But could he find out a way to stop his roller skates?

    Students learn their lessons in class. In class, teachers teach them. Students sit in the classroom listening to the teacher. Is this the only way for students to learn? Of course not. There is another way to learn. That is, students can teach themselves. For example, if you cannot remember anything when you are doing your homework, you can look through（浏览） your book to find the answer. This is a way to teach yourself. And it's not a difficult thing. We can do it at any place and at any time.

    How to teach yourself? The first thing you must do is to read. Read something interesting. The second is that you must ask yourself questions. Many clever students often do this. The questions are about something you don't understand or you want to know more about. You can write down these questions. The third is to answer the questions yourself by thinking hard, by reading the texts or other books, and sometimes by asking other people. These are the ways of teaching yourself. And if you do these things for a long time, you can succeed（成功）in your study.

Shandong Province held the 36th Weifang International Kite Festival on the third Saturday of April in2019. A lot of kite fans from all over the world went there to join in the interesting festival on that day. Different kinds of beautiful kites flew in the sky.

Over 2, 000 years ago, a man named Gongshu Ban from Shandong Province invented a kite. It was made of bamboo. In the following centuries, kite-making developed well in China.

The first Weifang International Kite Festival was celebrated in 1984. In 1983, the Chairman of the Seattle Kite Association David Checkley took part in a kite show and later he visited several kite manufacturers(制造商). He found that kites made in Weifang were the best. He suggested holding the first Weifang International Kite Festival there. After that, Weifang began to hold it in April every year.

At the fifth festival, Weifang became known as the" Kite Capital of the World". Today, Weifang is home to over 300 kite factories. People in Weifang sell their products to about 40 countries and regions(地区) , making up 85 %of the domestic(国内的)markets and 65 %of the foreign markets.

However, there are also some problems. "Few people would like to learn about traditional kite-making," said Yang Hongwei. Yang's grandfather was once one of the best kite makers in Weifang. Nowadays, Yang still uses traditional ways and skills to make kites. In her opinion, only traditional things can last for a long time. Since the1990s, she has travelled to many countries to teach and take part in kite shows. "I won't stop teaching the ways of making kites as long as someone wants to learn. Meanwhile, the government should hold more kite festivals in China or even overseas, "she said.

People often think of the North Pole and the South Pole as similar frozen wastelands. They are both places with very cold temperatures and few people live there. However, the North and South Poles are not much alike as people may imagine. 

The North Pole has no land, only thick ice. Temperatures seldom go above 32°F, at which water turns into ice. Most of the time, it stays below zero. In winter temperatures are usually as low as-30 F. 

Although conditions were very poor, people tried for many centuries to reach the North Pole. More than 100 years ago, two men, Robert Peary and Mathew Henson, were able to get to this environment full of troubles and difficulties. They reached the North Pole on March 8th, 1909. It was really a hard trip for them. 

There are few things more dangerous than crossing the Arctic on foot, People who stayed there may face many problems: very cold temperatures, sudden storms, and even hunger. Most of the area is uninhabited. Few people can live in such a difficult place. 

People might think that with such low temperatures for most of the year, the ice would be thick and hard. However, this is not true in the Arctic. The movement of the ocean water under the ice may often cause many different changes on the surface. Sometimes the ice breaks into two opening lanes of water called "leads". Anyone who falls into a lead can be frozen to death in a few minutes. 

" Am I an'I' person or an 'E' person?" It is a popular topic among young people around China today. Many people are crazy about it so that they take a personality test named MBTI to find out the answer.

Many people find the test useful. It groups people into 16 types, which start with the letter"I"or" E", such as" ENTJ" and"INFP"." E" is short for" Extroversion" while"I" is short for" Introversion". After testing, some say," I'm extroverted; I should go to parties and make friends," while others think," I'm introverted; I prefer working alone, and maybe I' ll be a writer someday." They believe knowing their type can help them make quicker choices about activities, careers, and life paths.

However, there are some problems with the test. Some get different results when they retake it, and some find it hard to answer certain questions. For example," I like watching TV alone, but I also enjoy hanging out with friends. Am I an'I' person or an'E' person?"

When you take a personality test, you may think," Oh, that's me." That's because the descriptions are generic. They can be used to describe many people. Research has found that over50% of people got a different score when they retook the MBTI test just five weeks later. Personalities can change with time, and they are not black- or- white, scientists say. You may be introverted now but become extroverted when you get older. Or, you can be both an"I" person and an"E" person. Don't label(贴标签) yourself! Studies have also shown that the test is not real at telling people's success in different jobs. So, don't take it too seriously.