Answer:
Bothered by allergies, some high schoolers missed several days of school last fall.
Step-by-step explanation:
A concise sentence is a sentence that relays all the necessary information without using unnecessary words. The given sentence can be rewritten as:
- Bothered by allergies, some high schoolers missed several days of school last fall.
The explanation of what allergies are (a condition that made them sneeze) can be omitted as it's not necessary.
The construction some of the can be shortened to some.
The explanation of why exactly high schoolers missed school is also unnecessary. As soon as we're told that they missed school due to allergies, we can guess that they're having sinus troubles. This is implied information.