This year’s Nobel Prize for Physiology or Medicine     1     Tu Youyou, whose research led to the discovery of artemisinin,     2     for malaria. Artemisinin has saved hundreds of thousands of lives, and has     3     for millions of people.

These smart homes will keep us secure, save us energy, and     4     .

Many of these new innovations     5     in some homes.

This four-day     1     tour will take you on amazing     2     through the Andes Mountains on the way to the city of Machu Picchu.     3     reaching your     4    , you will have a day to     5     and be amazed by this     6     city.     7     amazing is the Incas’ dry stone method of building. Inca builders cut stones     8     exact sizes so that nothing was     9     to hold walls together other than the perfect     10     of the stones.

Customs play a significant role in festivals, but sometimes they can change     1     time. With the development of modern society and the spread of new ideas, some traditions may     2     away and others may be established. One example is the     3     Chinese Spring Festival custom of lighting firecrackers to drive away the evil     4     and celebrate the new year.     5    , many big cities have given up this custom in order to     6     air pollution. Another example is Halloween, which slowly became an exciting festival for children, in spite of its     7     origins.

Festivals are becoming more and more commercial, with business     8     advantage of the celebrations. Online shopping websites and     9     media apps have made it much easier for the public to spend more on gifts for their     10     ones. Although some believe festivals should not be commercialized, others believe the increase in spending is good for the economy and public happiness.

Imagine having the     1    to sing together with hundreds of other people while you are at home alone. You can do this in a virtual choir. Virtual choir members record themselves while they    2         alone on video. These videos are uploaded     3    the Internet, and then they are put together into one video that you can see online-a virtual choir.    4    can take part in a virtual choir from anywhere-    5    you need is a video camera and an Internet connection. You do not even need a     6    . A virtual choir helps connect     7     people together. Many people do not have close friends or contacts who have the same interest in music. Many others do not have the chance to join a local choir. A virtual choir    8    them to add their voices to those of other individuals and become part of the global community. It has     9     to be a positive influence on the lives of many people. As one virtual choir member said,”Music helps me to... forget my problems. With music, I become someone     10     .”

But hope was not lost. Soon after the quakes, the army sent 150,000 soldiers to Tangshan to dig out those who were     1     and to     2     the dead. More than 10, 000 doctors and nurses came to provide medical care. Workers built     3    for survivors     4     homes had been destroyed. Hundreds of thousands of people were helped. Water and food were brought into the city by train, truck, and plane. Slowly, the city began to     5    again.

Tangshan started to     6     itself and get back up on its feet. With strong support from the government and the tireless     7     of the city’s people, a new Tangshan was built upon the earthquake ruins. The new city has become a     8     to more than seven million people, with great improvements in transportation, industry, and environment. Tangshan city has proved to China and the rest of the world that in times of disaster, people must     9     and show the     10     to stay positive and rebuild for a brighter future.

Economic development is necessary if we want to     1     society. There comes a time     2     the old must give way to the new, and it is not possible to     3     everything from our past as we move towards the future. Finding and keeping the right     4     between progress and the protection of cultural sites     5     be a big challenge.

Big challenges, however, can sometimes lead to great     6    . In the 1950s, the Egyptian government wanted to build a new dam across the Nile in order to control floods, produce electricity, and     7     water to more farmers in the area. But the     8     led to protests. Water from the dam would likely damage a number of temples and destroy cultural relics that were an important part of Egypt’s cultural     9    . After listening to the scientists who had studied the problem, and citizens who lived near the dam, the government     10     to the United Nations for help in 1959.