Napping means     1     (sleep) lightly or briefly. The best thing about napping is that you can do it anywhere, on your classroom desk, in the workplace chair,     2     even inside the bus. You can take a nap for 10 minutes,20 minutes, 30 minutes, etc; that depends on your     3    (convenient). The benefits you get from napping     4     (be) almost the same as those from sleeping. Napping helps you to stay     5     (energy) and focused, improves your memory, uplifts your mood and best of all makes you a creative person.

There are some simple rules     6     (follow) about taking a nap. First,     7     it’s possible, nap at the same time every day. Next, make your napping time short and sweet. You will feel even     8     (bad) if you wake up from a long deep sleep. Also set an alarm clock. In that way, you can get     9     (full) relaxed during your nap. You won’t have to keep looking at the clock.

Next time you feel sleepy after lunch, close your eyes and take a nap,     10     will surely do you a lot of good.

Singing is one of those universal actions that everyone can do for fun, regardless of how they sound. According to recent studies     1    (conduct) at Goethe University Frankfurt, singing can be actually helpful to your immune system. The study focused     2     a group of people who sang in a professional choir and discovered that the amount of proteins in the blood that function as antibodies (抗体) was     3    (obvious) higher after singing, so people involved in music could be less likely     4    (get) sick.

Singing actually is the perfect physical exercise for people who are injured, disabled or elderly. Not only     5    (do) singing help increase your lung capacity, but it helps stimulate circulation. This can lead to better results when people hit the gym thanks to the person’s increased aerobic (有氧的) capacity and newfound physical or mental strength.

The simple truth is that singing makes you happy. It releases endorphins (内啡肽), a chemical     6     reduces pain and makes you feel     7    (happy) and less stressed. People who sing, especially in choirs and on the stage are known to have better social skills and be loss lonely.     8    (stand) on the stage and performing can be tough,     9     when you do it in a group, it can help improve your sense of self as well as increase your     10    (confident).

Physical activity is shown to lessen the effects of aging     1     the brain. Experts say that dancing is great at involving all the brain functions at the same time---from musical and kinesthetic (运动的), to rational and     2    (emotion). Dancing pumps blood to the brain, giving it the glucose and oxygen needed to function well. So    3    is of great benefit to do this great activity. Dancing increases neural (神经的) connectivity----therefore making you the smarter person you have always hoped you would be.

When were you born? For most people, this is an easy question. Even those who don’t know their exact birthday can usually figure out when they were born to within a few years. Yet the Internet is full of quizzes    1     (make) to help you determine in which decade you were born. These are usually based on what    2     (happen) in American pop culture at the time you first became aware of it. It sounds foolish. But many people, though    3     (complain) about the stupid quizzes, still take them, wondering     4     their answers generate their correct birth year.

Population Growth in Nineteenth-Century Europe

Because of industrialization and a vast increase in agricultural output, in Europe as a whole, the population rose from 188 million in 1800 to 400 million in 1900. By 1900, virtually every area of Europe     1     (contribute) to the tremendous surge of population.

Improvements in the food supply continued trends that had started in the late seventeenth century. New lands were put under cultivation, while the use of crops of American origin, particularly the potato, continued to expand. After 1850, the expansion of foods more regularly kept pace with population growth,     2     the poorer classes remained malnourished.

Two developments were crucial. First, the application of science and new technology to agriculture increased. Led by German universities, an increasing number of researches     3     (devote) to improving seeds, developing chemical fertilizers, and advancing livestock. Mechanization included the use of horse-drawn harvesters and seed drills, many     4     (develop) initially in the United States. The second development     5     (involve) industrially based transportation. With trains and steam shipping, it became possible to move foods to needy regions within Western Europe quickly. Famine became a thing of the past.

Europe's population growth had included one additional innovation by the nineteenth century - rapid urbanization. With a growing number of people    6     (press) available resources on the land, people crowded into cities to seek work or other resources. During that period, urban death rates remained high, particularly in the lower-class slums, but they began to decline rapidly     7     urban sanitation (卫生) was greatly improved.

Reformers, including enlightened doctors, began to study the causes of high death rates and to urge reform. For instance, Edwin Chadwick led an urban campaign for underground sewers (下水道) in England in the 1830s. Gradually, public health provisions began to cut into customary urban mortality rates. Around 1900, in some parts of Western, Europe life expectancy in the cities began to surpass     8     of the rural areas. Industrial societies figured out ways to combine large and growing cities with population growth, a development that would soon spread to other parts of the world.