Crossword Puzzle Attain a maximum level of competence

Clue: Attain a maximum level of competence

Highest level attainable (ACME with 4 letters)
Low-level Navy officer (abbr.) (ENS with 3 letters)
Amtrak ride that offers high-level math courses? (CALCULUSTRAIN with 13 letters)
Attained, as as office (ACCEDED with 7 letters)
Attainment levels (PLATEAUS with 8 letters)
Attain an honor (ACCEDE with 6 letters)
Attain (e.g. ACHIEVE with 7 letters)
Entry-level legal jobs: Abbr. (ADAS with 4 letters)
Top-level domain for the aviation industry (AERO with 4 letters)
Maximum amount (e.g. ALL with 3 letters)