3. What is the main idea of the second paragraph?
A) Some plants have relative immunity to a great many diseases, while others have a
susceptibility to them.
B) The tolerance of a particular plant changes as the growing condition change.
C) A blight killed virtually every chestnut tree in North American.
D) A blight may be a national infection.
4. According to the passage, some plant diseases can be prevented by
A) killing parasites.
B) inoculation
C) Killing insects
D) improving growing conditions
5. Which of the following statements is not true?
A) Some plant diseases may be caused by bacteria.
B) Some plant diseases may be caused by pathogens.
C) Some plant diseases may be caused by fungus.
D) Symptoms are always helpful in identifying diseases.
Keys: DDABD
A) Some plants have relative immunity to a great many diseases, while others have a
susceptibility to them.
B) The tolerance of a particular plant changes as the growing condition change.
C) A blight killed virtually every chestnut tree in North American.
D) A blight may be a national infection.
4. According to the passage, some plant diseases can be prevented by
A) killing parasites.
B) inoculation
C) Killing insects
D) improving growing conditions
5. Which of the following statements is not true?
A) Some plant diseases may be caused by bacteria.
B) Some plant diseases may be caused by pathogens.
C) Some plant diseases may be caused by fungus.
D) Symptoms are always helpful in identifying diseases.
Keys: DDABD