Some people are pessimistic when they think about the future. They say that, a hundred years from now, we will have used up most of the earths resources. We will have made our seas so dirty that we will not be able to eat fish from them. There will be so many people in the world that we will have to use all the countryside for housing; there will be no farmland left. Other people have a different idea about the future. In their view, the city of the future will be a huge pyramid-shaped building, which will be floating on the surface of the sea. About 5,000 families will live there, and there will also be schools, shops in it. In a hundred years' time, people will not need to use oil. They will heat their homes with power from the sun. Think of space. Perhaps a station will be set up on the moon; people will be able to visit the moon as tourists. They may even spend their holidays in space, travelling from planet to planet. What an interesting picture! Many people don't think about the future. "I don't care. I'll be dead. "they say. But it is our duty to care because the world of a hundred years' time will be the world of our children's and their children after them. The writer of the article seems to agree _ . A) with those who look at the bright side of the future B) with those who take a pessimistic view about the future C) with those who won't trouble their heads about the future D) to none of these viewpoints
A
As more people use smart phones to pay bills and store personal information, strict password security has become more important than ever. A new study shows that free - form gestures - sweeping fingers in shapes across the screen of a smart phone--can be used to unlock phones. These gestures are less likely to be observed and reproduced by others than traditional typed passwords. "All that it takes to steal a password is a quick eye," said one of the researchers of the study. "With all the personal information we have on our phones today, improving their security is becoming increasingly necessary." In developing a secure solution to this problem, the researchers studied the practicality of using free - form gestures. With the ability to create any shape in any size and location on the screen, the gestures were popular as passwords. Since users create them without following a template, the researchers predicted these gestures would allow for greater complexity. The researchers carried out a create - test - retest experiment where 63 people were asked to create a gesture, recall it, and recall it again 10 days later. The gestures were captured on a recognizer system designed by the team. Using this data, they tested the complexity and accuracy of each gesture using information theory. The result of their analysis is that people are favorable to use free - form gestures as passwords. To put their analysis into practice, the researchers then had seven students in computer science and engineering, each with considerable experience with touchscreens , attempt to steal a free - form gesture password by observing a phone user secretly. None of them were able to copy the gestures with enough accuracy. The gestures appear to be extremely powerful against attacks. Though the testing is in its early stage and widespread adaptation of this technology is not yet clear, the research team plans to continue to analyze the security and management of free - form passwords in the future. They believe this is the first study to... The main purpose of the text is to _ . A) advise people to use free - form gestures B) discuss whether smart phones are safe C) talk about the practicality of passwords D) introduce the study of a new password
D
Q: More than 2 million US teenagers have suffered a serious bout of depression in the past year, according to a federal government survey released on Tuesday. On average, 8.5 percent of adolescents aged 12 to 17 described having had a major depressive _ in the previous year, the Substance Abuse and Mental Health Services Administration reported. But there were "striking differences" by sex, with 12.7 percent of girls and 4.6 percent of boys affected. Depression is the leading cause of suicide, which in turn is the third-leading cause of death for 15- to 24-year-olds in the United States. "The data Combined 2004 to 2006 data showed that rates of past year major depressive experience among youths aged 12 to 17 generally increased with increasing age," the researchers wrote. Researchers at SAMHSA and RTI International in Research Triangle Park, North Carolina, prepared the report using data from the National Survey on Drug Use and Health. More than 67,700 youths aged 12 to 17 answered questions about mood and depression. They were also asked to rate how depression affected them using the Sheehan Disability Scale , which measures impact on family, friends, chores at home, work and school. Researchers defined a major depressive episode as two weeks or longer of depressed mood or loss of interest or pleasure, and at least four other symptoms such as problems with sleep, energy, concentration or self-image. Nearly half of the teenagers who had major depression said it severely damaged their ability to function in at least one of the areas on the disability scale. "Fortunately, depression responds very well to early intervention and treatment," SAMHSA Administrator Terry Cline said in a statement. What can be implied, but is not stated directly? A) depression is the third-leading cause of suicide. B) There were over 2 million American teens suffering depression in the past two years. C) The students surveyed were aged between 12 and 17. D) There were more girl students suffering depression than boys.
A: D
(Q).
Once Lu Xun spoke to the young men about the study of foreign languages. He said: " You must not give up studying foreign languages for even a day. To master a language, words and grammatical rules are not enough. You must do a lot of reading. Take a book and force yourself to read it. At the same time, turn to dictionaries and memorize grammatical rules. After reading a book, it's only natural that you won't understand it all. Never mind. Put it aside, and start another one. In a few months or half a year, go over the first book again; you are sure to understand much more than before ... Young people have good memories. If you memorize a few words every day and keep on reading all the time, in four or five years, you will certainly be able to read works in the foreign language. This passage mainly tells us how to _ A) do our reading B) turn to dictionaries C) memorize new words D) use grammatical rules
(A).
A