单选题What does the word "stamped" in Para. 3 mean?

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单选题It can be inferred from the passage that children are likely to________when they are asked to count all the halls of different colors.

单选题{{B}}Passage Two{{/B}} The "modest" success of an HIV "vaccine (疫苗) clinical trial in Thailand is turning out to be even more modest than originally advertised. Full details of the study, released in Paris, show that the vaccine provides no protection to people at the highest risk of HIV infection. In people at lower risk, the benefits may start to decrease after a year. Furthermore, when the results of the three-year experiment are analyzed using alternative methods, the protective effect falls short of formal statistical significance. Despite the new warning, many AIDS researchers say the findings are still important. Some other observers, however, think the results have been oversold in a potentially damaging way. Initial results of the RV144 trial were revealed through a press release and interviews in late September. The presentation in Paris provided much more detail, as does a paper released at the same time by the New England Journal of Medicine, where it will eventually be published. The effort to make an HIV vaccine has been dogged(固执的) by failure for two decades. The Thai trial, which employed a two-component vaccine and a total of six injections, was the first to show protection. Only 132 became infected among the 16,402 Thai men and women ages 18 to 30 years old who volunteered for the study. The trend suggested that the vaccine provided protection, but the results were not statistically significant by the definition used in most medical research. When counting only people who received all six injections on schedule, which reduced the total sample by 30 percent, there was also a trend toward protection, although not a significant one. When the researchers excluded seven people who were already infected when the trial started, however, the results significantly favored the vaccine. It reduced the chance of becoming infected by 31 percent. Nelson L. Michael, an Army physician with the U. S. Military HIV Research Program, said it best reflected a real-world use of the vaccine. Not everyone can be expected to follow a complicated shot schedule perfectly, so it was reasonable to include people who didn't receive all six injections, he told reporters in Paris. He said it was also reasonable to exclude people who were already HIV-positive before the study began.

单选题Questions 5 to 7 will be based on the following news item.

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单选题Only those who can ______ to lose their money should make high-risk investments. A. maintain B. sustaint C. endure D. afford

单选题Directions: In this section, you will hear 3 short passages. At the end of each passage, you will hear some questions. Both the passage and the questions will be spoken only once. After you hear a question, you must choose the best answer from the four choices marked A, B, C and D. Passage One Questions 16 to 18 are based on the passage you have just heard.

单选题With cancellation insurance, you can ______.