Once upon a time, there was a salt seller. He had his business on the market and his donkey(驴子) helped him to carry salt bags every day.

On the way to the market, they had to cross a river. One day, the donkey suddenly fell into the river. The big bags of salt also fell into the water. The salt seller didn’t notice that some of the salt dissolved(溶解的) in the water, making the bags much lighter to carry. The donkey realized this and felt much more ____ on his way to the market.

The next day, the donkey did the same thing, but this time, he fell in the water ____. Again, the bags were lighter and easier to carry.

The salt seller soon found out what was going on and ____ to teach his donkey a lesson. The next day, he put two big bags of cotton on the back of the donkey. Again the donkey played the same trick, hoping that the bags would become even lighter.

But the cotton that fell into the water became very ____ to carry. The donkey learned a lesson and didn’t play this trick anymore after that day.

Sometimes, taking shortcuts or cheating may make things easier, but they often come back to ____ us later. It is better to simply work honestly.

Do you know Beijing Opera? It is known as the most famous of all Chinese traditional dramatic art forms and the largest Chinese opera form. Having a history of about 200 years, it is developed from many other dramatic _______, mostly from the local drama “Huiban”, which was _______ popular in South China during the 18th century.

Theatrical art forms in many other countries do not _______ singing, dancing and spoken parts together in one single drama. An opera singer neither dances nor speaks _______ stage. In a dance drama, the dancer has no speaking role and does not sing _______.

_______ in China, Beijing Opera has spread to many other places. Mei Lanfang, one of the most famous _______ of all time, was the first to introduce Beijing Opera to foreigners and made highly successful tours to foreign countries.

“You may be at lost when you first watch Beijing Opera but a little _______ gradually. You will be strongly attracted to Beijing Opera even if you know _______ of the dramatic background.” This is how one American ________ described his first experience in watching Beijing Opera.

Beijing Opera is China’s national opera and it is full of Chinese cultural traditions. Welcome to China and enjoy Beijing Opera!

Wind power is a very clean source of energy. This is how wind power works. Wind makes windmills spin（旋转）. When the windmills spin, they make electricity.

A lot of people think that wind power is new, but that’s not true. For thousands of years, people have used wind to sail boats and move water. We still do those things today, but these days we mostly use wind power to make electricity.

Wind power is a very popular source of energy. △ First of all, it’s clean. Windmills don’t pollute the environment at all. Second, we can use wind power forever. After all, we will always have wind. Also, wind power is cheap, and it’s getting even cheaper.

A lot of people don’t understand wind power very well. They believe that there are problems with wind power, but many of those problems are not real. For example, some people say that windmills are dangerous for birds. Old windmills killed birds because they spun very fast. New windmills spin slowly, and they aren’t dangerous for birds.

However, there are real problems with windmills. One problem is that many people think windmills are very ugly. This is a problem for people, because windmills are often in very pretty areas. Also, wind doesn’t blow all the time, so we can’t use wind power all the time. Finally, windmills are noisy.

Wind power is becoming more and more common. Right now, more than 80 countries use wind power. About 2.5 percent of the world’s power comes from the wind. For some countries, that number is a lot higher.

The vaccines China is now using are called “inactivated vaccines”（灭活疫苗）. There are no living viruses in these vaccines. They cannot cause the disease, but can show your body what the virus looks like and make you immune（免疫）to it. Studies show that China’s vaccines are 79.34 percent effective. If 79 percent of the whole population becomes immune, the possibility of COVID-19 spreading will be very low.

The vaccine is given by injection（注射）. It’s advised to get two doses（剂量）. You should wait about two weeks after the first dose to get the second one. The vaccines have been tested among three different age groups: 3 to 17, 18 to 59, and 60 and above. The 18-to-59 age group has the most data—the vaccines have been proven to be safe to this group. Experts suggest people from the age of 18 get vaccinated. But people who have serious diseases such as cancer（癌症）or diabetes（糖尿病）, or people who are allergic（过敏的）to any of the vaccine’s ingredients, should not get it. People who want to get the vaccine should not get any other vaccines during the same period. It takes a few weeks for the body to build immunity after vaccination. There’s also a small chance that your body won’t build immunity. So before the population becomes immune to the virus, it’s highly encouraged to keep wearing masks and washing your hands after getting vaccinated.