For a long time, the role of carbon dioxide in the atmosphere has been positive and negative: the increase in its concentration can promote the accumulation of photosynthetic products in terrestrial ecosystems, increase soil carbon storage, and form soil carbon sequestration effects. This is a positive effect. It will also increase greenhouse gas emissions such as methane and nitrous oxide from terrestrial ecosystems, and exacerbate the greenhouse effect, which is a negative effect. Therefore, carbon dioxide still has the most negative effects on the atmosphere. Which of the following _______ items can explain the conclusions in the stem. ['Soil carbon sequestration effect of carbon dioxide formation is more important than the greenhouse effect.', 'Carbon dioxide is an essential raw material for plant photosynthesis, and its content is good for plants.', 'Whether the increase in carbon dioxide concentration is good or bad depends on how humans use it.', 'According to observations, the greenhouse effect of carbon dioxide offsets and exceeds the carbon sequestration effect.']