Final answer:
In the sentence provided, the adverb 'almost' modifies the adjective describing the amount of money raised. It indicates that the figure is close to but not exactly one million dollars.
Step-by-step explanation:
The adverb that modifies an adjective in the sentence 'Today we have raised almost one million dollars to send to the victims of the flood' is 'almost'. This adverb modifies the adjective 'one million', emphasizing that the amount raised is near but not quite one million dollars. The use of 'almost' here serves to modify the extent or degree of the adjective that follows.