Which of the following is TRUE about plants？
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The word“proper”in the first line of the second paragraph means＿＿＿.
How did the man feel about his work？
为正确选择采样点、采样对象、采样方法和采样时机等，必须在采样前对工作场所进行现场调查。采样前的正确调查工作是（）。
听下面一段材料，回答 6～7 题。
第 6 题 Why is the man so annoyed？
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