分页:
上一页 1 2 3 4 5 6 7 8 [9] 10 下一页
D) delayed treatment of the flu will harm the liver and central nervous system
23. According to the passage, to combat the flu effectively,
A) one should take medicine upon catching the disease
B) one should identify the virus which causes it
C) one should consult a doctor as soon as possible
D) one should remain alert when the disease is spreading
24. Which of the following symptoms will distinguish the flu from a cold?
A) A sore throat.
B)A stuffy nose.
C) A dry cough.
D) A high temperature.
25. If children have flu-like symptoms, their parents
A) are encouraged to take them to hospital for vaccination
B) are advised not to give them aspirin
C) should watch out for signs of Reye syndrome
D) should prevent them from mixing with people running a fever
Passage FOUR
Questions 21 to 25 are based on the following passage.
Lead deposits, which accumulated in soil and snow during the 1960's and 70's, were primarily the result of leaded gasoline emissions originating in the United States. In the twenty years that the Clean Air Act has mandated unleaded gas use in the United States, the lead accumulation world-wide has decreased significantly.
In his new study, Dr. Boutron found the ratios of the different forms of lead in the leaded gasoline used in the United States were different from the ratios of European, Asian and Canadian gasolines and thus enabled scientists to differentiate ( 分区) the lead sources. The dominant lead ratio found in Greenland snow matched that found in gasoline from the United States.
分页:
上一页 1 2 3 4 5 6 7 8 [9] 10 下一页