1 . Previously, the most readily available invisible ink was lemon juice. To use it, write with the lemon juice on ordinary paper, iron the paper with a hot iron and the hidden message will appear. The disadvantage is that the paper has to be destroyed to hide the message so no one else can read it.
Scientists have discovered a new kind of invisible ink. It is called water. All you need for this secret-messaging ink to work is to write with it on a super-hi-tech piece of paper coated with special chemicals. Shine a UV light on the coated paper and the water message becomes visible.
When the message has been read and needs to be hidden again, get out your hairdryer, and blow some warm air on the paper. Then the message will be erased and the paper can be reused, which keeps costs low.
The chemicals on the paper take in and give off light. The scientists found that putting water on the paper broke up the structure of the chemicals it was coated with. The water writing showed up darker than the surrounding paper under UV light.
Using hot air from a hairdryer for 15-30 seconds, you were able to reuse the special paper as many as 30 times because the heat reorganized the chemical structure of the paper coating. Without the heat from a hairdryer, the message stayed visible for up to three months.
The invention was made by a group of scientists in China, led by Qiang Zhao of the Institute of Advanced Materials, Nanjing University of Posts and Telecommunications.
1. What does the underlined word “it” refer to in Paragraph 2?| A．Paper. | B．Ink | C．Light | D．Message |
| A．be read | B．be erased | C．become darker | D．become visible |
| A．3 times | B．15 times | C．20 times | D．30 times |
| A．A Magic Hairdryer | B．A Special Chemical |
| C．A New Invisible Ink | D．An Environment-friendly Paper |
2 . Anderson Carey is 12 years old. One day, he saw a magazine article that interested him.
It was about prosthetics(假肢), which can be used to replace a hand, arm or leg.
The article said people are using 3-D printers to build these devices. Anderson thought this was very cool. He wanted to learn more about it. So Anderson talked to his science teacher, Dr. Holly Martin. He asked if they could build a prosthetic together. The timing(时机的把握) was perfect. Martin had just heard about a group called Enabling the Future. This group asks volunteers to help to build robotic arms and legs. The volunteers build them for people who share their stories on the website.
Anderson and Martin looked through the website together. They decided to help a man from the country of Romania. His name is Cornel Crismaru, who lost his leg, hand and part of his arm.
In February, Anderson and Martin got to work. Building the robotic arm was not easy. Anderson ran into some problems along the way. He had hoped to use a 3-D Printer at his school. One of the pieces for the arm was bigger than the size of the printer, though.
Soon Anderson had an idea to solve this problem. He reached out to a 3-D printing company in Woodstock, Georgia. The company agreed to help. Anderson and Martin could use their big 3-D printers. After that, Anderson worked on the arm for about three months.
Anderson and Martin sent the arm to Crismaru in May. In August, they received a notice. It is from Crismaru’s son. He thanked Anderson and Martin for their help.
Martin said she hopes children and grown-ups who hear about Andersons projects will realize that it may be hard to change the world, but they can start with small acts. Some of these can help a person in a huge way.
1. Anderson talked to his science teacher about_______.| A．starting a website together | B．buying a 3-D printer |
| C．building a prosthetic together | D．studying robots |
| A．lost some body parts | B．wanted to be a volunteer |
| C．was homeless | D．was interested in robots |
| A．He made a new 3-D printer. | B．Hе took Dr.Martin’s advice. |
| C．He worked together with his school. | D．He got help from a 3-D printing company. |
| A．All roads lead to Rome. | B．Failure is the mother of success. |
| C．Those who help others help themselves. | D．Small acts make a big difference. |
3 . Pizza is almost everyone’s favorite food. Recently, it has even received recognition from UNESCO (United Nations Educational, Scientific and Cultural Organization)!
Pizza has been a part of Italian culture for centuries. In the 1700s and the 1800s, the city of Naples in Italy was an independent kingdom, known for its large working class. Pizza began as a “poor man’s food”— as a way to feed poor people quickly and at a low cost.
In 1889, King Umberto Ⅰ and Queen Margherita visited Naples, which had by then come under a unified Italy.
When Italians from Naples moved to the United States, they brought more than just their desire for a better future.
The art of pizza spinning.
The skills for pizza making have been passed down in the city for generations, and those who know them are called “pizzaiuoli”.
According to UNESCO, about 3,000 pizzaiuoli work in Naples right now. In the city, there is also a pizza museum and an academy in which 120 students each year can train to become pizzaiuoli themselves.
| A．The history of pizza |
| B．The popular types of pizza |
| C．Pizzaiuoli are a select group of people |
| D．Pizza shops opened in New York and other cities |
| E．On their visit, the royal couple enjoyed pizza from a local eatery |
| F．Pizza fans and pizzaiuoli alike are excited about UNESCO’s decision |
| G．On the streets of Naples, Italy, tradition is found in the art of pizza spinning |
4 . It’s hard to imagine that just 25 years ago, Berlin was a city split (分开) into two by the Berlin Wall. I’ll never forget how people were excited as the Berlin Wall came down in 1989. Since then, Berlin has become one of the coolest cities in Europe. Here are the main reasons why I think Berlin is cool.
It’s affordable. Berlin has cheap hotels and everyday objects. You don’t have to worry about spending too much money when visiting Berlin.
It has fantastic festivals. Berlin knows how to give parties, and there is a festival here every month of the year. Perhaps the most famous is the Berlin International Film Festival.
It has great architecture (建筑设计). Berlin has beautiful architecture of its own. The Brandenburg Gate, built in the 18th century, is one of the city’ s most famous buildings, symbolizing more than 200 years of history. The TV Tower is as good as the Eiffel Tower in Paris and the London Eye.
The art scene is flourishing (繁荣). Berlin is a city of living art. Artists are allowed to create works of art on the sides of buildings.
If you want to visit an affordable European city with culture and lots of colors, Berlin is the place to be. What are you waiting for? Get to Europe’s coolest city before everyone else discovers it.
1. The underlined word “affordable” in Paragraph 2 means “________” in Chinese.| A．可利用的 | B．可触及的 |
| C．付得起的 | D．用得住的 |
| A．Once a week. | B．Twice a week. |
| C．Once a month. | D．Twice a month. |
| A．Its color. | B．Its history. |
| C．Its location. | D．Its architecture. |
| A．He can’t stand it. | B．He thinks it’s boring. |
| C．He doesn’t mind it. | D．He thinks it’s cool. |
5 . The measurable threat to the environment has been worsened by the spread of COVID-19 that increases the need for plastic protective equipment. Most plastic is made from fossil fuels. Millions of tons of greenhouse gas are released from the development of these resources and plastic production and burning.
The end life of plastic is just worrisome. Less than 10% of the plastic produced has been recycled. Even more of it has been burned. But the vast majority of plastic has been buried inland, and it is increasingly polluting the environment. We hear mostly about ocean plastic and the harm done to sea creatures that mistake plastic bags and bits for food. But microplastic is even more worrisome. Plastic doesn't break down biologically but instead breaks down into tiny particles（a very small piece of something）, which have been found in every corner of the planet, on land and in the air, in drinking water and food sources.
Yet the public has not given this global environmental disaster the attention it requires. Instead, they have viewed single-use plastic—which makes up about 40% of plastic used each year—as a litter issue that can be solved through better recycling and waste management. That attitude must change because the recent global breakdown of the market for recycling has made it clear that it has never been, nor ever will be, able to keep up with plastic trash use.
California has been the forerunner of plastic waste reduction—it was the first state to ban single-use plastic bags and may be the first state to transform the way goods are packaged. The state also came close to passing an act which would have required that products sold in plastic packaging in the state have a proven recycling rate of 75% by 2032. California, though influential, can't solve this crisis alone. The US has long been producing a great amount of plastic trash and it should engage in reducing the use of plastic as well.
1. Why does the author mention the release of greenhouse gas in paragraph 1?| A．To show the harm of plastic |
| B．To warn of the climate change. |
| C．To call for the development of fossil fuels. |
| D．To highlight the importance of plastic equipment. |
| A．Favorable. | B．Tolerant. |
| C．Curious. | D．Opposed. |
| A．A pioneer. | B．A failure. |
| C．An objector. | D．A predictor. |
| A．Microplastic Products Are Harmful |
| B．Waste Recycling Is an Urgent Matter |
| C．Plastic Waste Pollution Is a Wake-up Call |
| D．Global Environmental Disasters Are Increasing |
6 . Everyone is afraid of something. Maybe you're afraid of spiders, or heights, or dogs, or the dark. And traditionally, we’ve thought that's because you learned to be afraid. Probably because you had a bad run-in with something at some point. But there's a different idea out there that's been getting more attention lately: the idea that fears aren’t just learned …they also can be inherited.
It sounds like a wild idea. How do you inherit something as abstract as fear? But over the last fifty years, researchers have been studying just how much fears have to do with inheritance and genetics. And their results have been kind of surprising.
In this work, they’ve put a lot of effort into understanding one extreme kind of fear, called a phobia. To get a sense of how much genes influence fear, scientists have begun looking at identical twins. Since identical twins have almost the same DNA, researchers can figure out how heritable a fear is by comparing how often specific phobias appear in identical twins as opposed to other brothers or sisters. Because even though twins often have lots of similar experiences, they probably don't share the types of experiences that cause phobias — like getting bitten by a dog or falling out of a tree.
One 1998 study of 659 pairs of identical and fraternal twins in Australia looked at how many had a fear of blood. The study found that genetics accounted for 71 percent of the variation among those people, meaning genetic factors play a pretty big role in determining whether a person has some specific fear.
A 2016 study also found that fear of dental work was over 30 percent heritable. So, if you are afraid of going to the dentist, it really might not be your dentist's fault. Overall, first-degree relatives of people with phobias are more likely to have similar phobias than people with no family history.
So, it's pretty clear that phobias are heritable!
1. What does the author mean by saying the underlined sentence in Para. 2?| A．It's unbelievable that people can inherit something so abstract like fear. |
| B．It's surprising that people know so little about inheritance and genetics. |
| C．It's natural that people become afraid of things that they had bad experience with. |
| D．It's interesting that people are afraid of so many things such as spiders and the dark. |
| A．They look very much alike. | B．They have shared experiences. |
| C．They have similar personalities. | D．They share basically the same DNA. |
| A．Dentists are scary to many kids. | B．Most people have some kind of fear. |
| C．Fear of blood is the most common phobia. | D．Fear of things can be a result of genetic inheritance. |
| A．A travel brochure. | B．A science talk show. |
| C．A commercial advertisement. | D．A history book. |
