set one's lips firmly [one's mouth in a firm line]
唇を固く(真一文字に)結んだ
set one's seal to ...
…に印を押す
set one's thoughts in order
考えを整理する
set out clearly the aims for learning
学習の目標を明確に立てる
set out for [on] an adventure
冒険に出かける
set out on a journey
旅立つ
set [put] pen to paper=take pen in hand
((形式))ペンを執る,書き始める
set phrases
慣用句
set posts in the ground
柱を地面に立てる
set some money aside for unexpected expenses
もしもの出費に備えて備蓄する