Have you ever forgotten where your socks are when you wake up in the morning? Can you remember what you     1     (eat) for lunch a week ago? You may think that being forgetful is not a good thing,     2     now you should be thankful.

Scientists from the University of Toronto found that forgetting is     3     (actual) a key part of learning, the Independent reported. Forgetting unnecessary information can help our     4     (brain) work better.

What kind of information is unnecessary? Scientists say that this may have something to do     5     the environment we live in.

In an environment that is always changing, our brains may require us     6     (remember) less. For example, a supermarket cashier meets many people every day and will probably only remember them for     7     short time. But a designer who often meets his or her clients will remember these people for much     8     (long).

That’s because our brains keep making new neurons from stem cells. There is a special area in our brains called the hippocampus (海马体). It enables     9     (we) to learn and remember things. The new neurons in the hippocampus help renew our old memories. This could explain     10     we still can remember so much about the time when we were very young.

As we all know, Hip-hop dancing is popular with many young people today. They like it partly     1    they can invent（发明）their own moves. It’s so free and     2    （excite）for the teenagers. They use this dance     3    （show）their love for life. It also shows that they feel good about life, that they just want to be themselves and enjoy life, and that they are not afraid of problems.

Hip-hop dancing has     4     history of more than 20 years. It     5    （one）began in the 1980s in the US. In early     6    （time）, it was seen in New York and Los Angeles. At that time, many young black people often     7    （dance）to the music in the streets. They used the legs, arms, heads and even shoulders to dance. Many young people still use most of these moves today.

Hip-hop dancing became popular all over the world because of the 1983 movie Flashdance. Some stars performed hip-hop dancing in the movie. Many audiences spent much time     8    （watch）their performance, and they began to dance     9    them. Then it became popular. There are two kinds of Hip-hop dancing: new school and old school. More and more young people are learning hip-hop dancing. People believe that it is a good way to exercise bodies and that it is good for     10    （they）health.

Artificial (人造的) light is necessary in our modern society.     1     the increased use of lighting can     2     /kɔːz/ some problems. Light in the wrong place and at the wrong time can disturb us.

How to     3     /prɪˈvent/ light pollution? Before answering the question, please think of a few simple questions: Is the lighting necessary? Could safety or security be achieved by other     4     (way)? Do the lights have to be on all night? Will it matter if we turn them     5    ?

If lighting is the best choice, then only the right number of lights for the task should be installed (安装). Lighting will then become a problem if lights are poorly designed or incorrectly installed.

If lighting     6     necessary, a number of ways can be taken to stop causing harm: For a family,     7     150W lamp is enough. High power (300/500W) lamps can     8     /kriˈeɪt/ too much light. As we all know too much light is sometimes     9     (danger). It can make our     10     (eye) lose sight for a short time. For an all-night porch(走廊), a 9W lamp is OK in most situations.

Make sure that lights are correctly adjusted (调整) so that they only make the surface bright and do not throw light onto unnecessary places.

According to the Chinese lunar calendar (阴历), 12 animals stand for 12 different years. Much to     1     (we) surprise, western people are also interested in zodiac (生肖) animals. The zodiac plays     2     important part in Chinese culture. It also has some social     3     (skill). People often ask “What is your zodiac animal?” With the question, you can find out which year someone was born     4     (easy).

Zodiac animals aren’t special to China. These days, many countries are     5     (share) a similar zodiac culture with China.     6     example, in Vietnam, they have a cat year while we have a rabbit year in China.

How were these 12 animals chosen? According to the legend, the Jade Emperor brought in the animals for Chinese New Year. There     7     (be) a game and he named a year for each one in the orders they arrived. The ox would have been the first to arrive.     8    , the mouse sat on his back and jumped off just before they arrived. So the mouse became the first one and the ox was the     9     (two). Do you think the mouse is the     10     (smart) one among all the 12 animals? If you can choose, which zodiac animal do you want to have?

Most Chinese like drinking tea. As the hometown of tea, China has rich tea culture. Chinese tea has a history     1     thousands of years. There are many kinds of tea in China. The six main kinds are green tea, black tea, oolong tea, yellow tea, white tea     2     dark tea. Among them, green tea is     3     most famous with the longest history.

How people drink tea shows Chinese tea culture. People use a tea set when making and drinking tea. A tea set is usually made     4     of a tea pot and some teacups. Different tea sets should be used for different kinds of tea. Also, people use different types of water when making different kinds of tea.

Drinking tea can do a lot of good to people’s health. For example, a cup of green tea can make them relaxed. And it can     5     help prevent illness. That’s why many people like drinking tea.

Lixia, or the Start of Summer, is the     1     (seven) of the 24 Chinese solar terms (节气). It is a goodbye to spring and a welcome     2     summer in China.

With the heat of summer, plants will begin to grow much     3     (fast). This is     4     best time of the year to plant early rice in South China. Chinese has plenty of old sayings that are     5     (use) to warn people not to be lazy.

In ancient China, people celebrated the day of Lixia in different ways. For example, people in some places cooked “Five-Colored Rice” which stood for people’s good wishes for a     6     (color) life. A more interesting food custom on Lixia was the way children played with eggs. On that day, children     7     (wear) a bag with a boiled egg around their     8     (neck), and had an egg fighting with their friends. They collided (碰撞)     9     one side broke the egg. The one whose egg was not broken won. They believed it could help keep     10     (they) safe and healthy.