Questions 8 to l0 are based on the following news from the VOA. At the end of the news item, you will be given 10 seconds to answer each question. Now listen to the news. Mir’s two primary sources of oxygen have stopped working and now ______ of oxygen inside Mir’s cab-in.

单项选择题At first, locomotives could not popularize themselves because they ______.

单项选择题The best way to save ozone is ______.

单项选择题According to the passage, one of the causes fur the difficulties of American higher education is that ______.

单项选择题According to the passage, what is one major criticism students often make of published research

单项选择题Why doesn’t the man accept the woman’softer