...作物产量增加量相等的天数，即为杂草的竞争临界期（Competition critical period）。 危害经济阈值（Economic threshold level）是防治后作物增收的效益与防除费用相等时的草害情况。
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The problem was not with the concept of debt intolerance, but rather with the portrayal of the 90 percent level as some sort of natural threshold beyond which economic growth rates would be severely curtailed.
FORBES: Narrow focus on debt and deficits distracts us from the primary problems
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