<span>D. Determined birdwatchers.
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A progressive form of a verb is formed with the ending "-in": the only verb form in the options that is formed with the ending "ing" is in option b.
The correct option is b: will have been falling. This tense is the future perfect progressive tense.
<span>Carbon is stored inside plants. When deforestation occurs or any other natural clearing of land, the carbon cycle is changed due to plants being removed that would have captured the CO2 and changed it to oxygen and also by the removal of large plants that store carbon being replaced with either small crops or concrete that do not store carbon.
In nature, fossil fuels release carbon very slowly over time, humans burn it at a much greater rate due to dependence on it, and burning fossil fuels emits a lot of CO2 into the atmosphere.</span>
1. When <span>using sources by authors with the same last name, you must always include the author's first and last name, to distinguish authors.
2. </span><span>If a source is written by multiple authors, you must place all of the authors' last names in the parenthetical citation. </span>
