The word "suspended" in the passage is closest in meaning to
A. grown
B. protected
C. spread out
D. hung
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According to paragraph 3, what is the advantage of hydroponics for research on nutrient deficiencies in plants？
A. It allows researchers to control what nutrients a plant receives.
B. It allows researchers to observe the growth of a large number of plants simultaneously.
C. It is possible to directly observe the roots of plants.
D. It is unnecessary to keep misting plants with nutrient solutions.
The word "facilitates" in the passage is closest in meaning to
A. slows down
B. affects
C. makes easier
D. focuses on
According to paragraph 2, a symptom of iron deficiency is the presence in young leaves of
A. deep red discoloration between the veins
B. white or yellow tissue between the veins
C. dead spots between the veins
D. characteristic dark green veins
According to paragraph 2, which of the following symptoms occurs in phosphorus-deficient plants but not in plants deficient in nitrogen or iron？
A. Chlorosis on leaves
B. Change in leaf pigmentation to a dark shade of green
C. Short, stunted appearance of stems
D. Reddish pigmentation on the leaves or stem
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