Are you trying to or just identify what it is ?
: Likely stands for Mid-School Multi-Resource or a specific district/state assessment acronym. U1 : Refers to Unit 1 .
The filename follows a naming convention typically used in educational software , specifically for benchmark testing or curriculum resources (likely related to English Language Arts). Technical Breakdown
: A compressed archive file. You need software like WinRAR or 7-Zip to open it. Likely Contents