Answer:
1) Almost
2)Everyone
3)Almost everyone finished the race
Explanation:
In the above given phrase, the modifier is "<em>ALMOST".</em> Modifiers refer to the words which increase the conception of a phrase, without affecting the main message being provided even if they are removed. Such that the grammar of a clause may not be affected if the modifier is removed.
Modifiers tend to directly affect the noun in most cases. Here, the modifier is affecting the noun "<em>EVERYONE"</em> since the phrase sentences 'everyone' finishing the race except a few others. Even when removed, the grammar of the sentence will not be compromised.
The resolution of the sentence is even more clears when it is converted into active voice.