D. 4.

23. How long can the capsule be taken continuously at most before it works? A. 4 weeks. B. Half a month. C. 1 hour. D. 30 minutes.

B

Have you ever noticed tiny raised areas on the branches of a tree? These may have been insects. These small insects feed on tree sap (汁液). Insects on urban trees are notably more abundant than those on rural trees. As a result, urban trees suffer from heavy infestations (害虫横行), and are often unhealthy or die. To protect and restore urban trees’ health, we need to determine the factors that make these tree pests more successful in urban habitats.

Living organisms interact closely with their environment. The warmer, more drought-stressed trees harbor more successful pests than cooler, less drought-stressed trees. As cities and natural habitats become hotter and drier, damaging insects will become more abundant on urban trees.

Trees within urban forests are valuable economically and for the environmental sustainability (可持续性) of the region. More than half of the world’s population lives in cities. Across the globe, people are moving into cities at a faster rate than ever. Rapid growth may turn cities into places with harder conditions. Although cities are primarily made of buildings, roads, parking lots, and vehicles, there are still plants in them. The trees within a city are referred to as the urban forest. Urban forests offer very big benefits to human and environmental health. They improve air and water quality, provide habitat for wildlife. cool down temperatures air and water quality, provide habitat for wildlife, cool down temperatures and beautify our environment. They make cities livable.

However, being a city tree is not easy. Heat released by human activities is trapped in cities. As a result, temperatures in urban areas are often warmer than their surrounding rural areas. We call this urban warming or the urban heat island effect. Urban habitats are mostly made of surfaces of asphalt (沥青 ) and concrete. These surfaces reduce the amount of rainwater that reaches tree roots. As a result, urban forests may suffer, which can negatively affect people and the environment.

What can we do to restore urban forests? Regular irrigation when possible may help keep pest populations under control. Planting tree species that are suitable to handle heat and drought stress would also reduce the occurrence of insect pest outbreaks.

24. Why do urban trees suffer from heavier infestations?

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A. Because urban insects are more abundant.

B. Because more people have come to cities. C. Because more tree sap can be fed on. D. Because cities become hotter and drier.

25. What causes the urban heat island effect according to the text? A. The use of asphalt and concrete. B. The lack of unban forests.

C. The heat that is trapped in urban areas. D. The lower temperatures in rural areas.

26. Which of the following word can replace the underlined word in Paragraph 5? A. Inspection. B. Watering.

C. Pest killing. D. Tree planting.

27. What would be the author’s purpose of writing the text? A. Call for people to protect urban trees. B. Display the importance of urban trees. C. Tell us methods to protect urban trees. D. Show how to solve the urban warming.

C

One form of social prejudice against older people is the belief that they cannot understand or use modern technology. Activities like playing computer games, going on the Net and downloading MP3s are only for the youngsters. Isn’t it unfair that older people enjoying a computer game should be frowned (皱眉) upon by their children and grandchildren?

Nowadays older people have more control over their lives and they play a full part in society. Moreover, better health care has left more people in their sixties and seventies feeling fit and active after retirement. Mental activity, as well as physical exercise, can contribute to better health. Playing computer games is a very effective way of exercising the brain.

When personal computers were first introduced, most older people didn’t believe they would ever familiarize themselves with it. Now computers have been around for a few generations and retired people have gradually become more relaxed about using them for fun. Gamers over 65 prefer playing puzzle games and card games. Kate Stevens, aged 72, says: “I find it very relaxing. It’s not very demanding, but you still need to concentrate.”

Another development that has favored “grey gamers” is a change in the type of video games available on the market. There’s a greater variety of games to choose from,

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