The case of the poisonous mushrooms (paragraph 2) suggests that American doctors ______.
The word “fluctuations” in paragraph 1, line 1 is closest in meaning to ______.
What does the author imply about lichens in Paragraph 1?
The word “they” underlined in Paragraph 4 refers to ______.
What is the more practical issue according to the fifth paragraph?
Which of the following statement is true according to paragraph 4?
The word “contain” underlined in Paragraph 3 means ______.
According to the third paragraph, which of the following is true?
It can be inferred from the last paragraph that the cultural activities in universities will grow if the government and individuals______.
The phrase “a ticking time bomb” in the second paragraph is used to stress _____