寒冷前線: cold front

air temperature, atmospheric temperature, ambient temperature

passage through an object / passage of a test in school / passage of a bill / passage through a screening

pass through something / pass a test / pass a bill / pass a screening

to hang (down) / to fall, descend / to stand back; to withdraw

descend / hand down an order, issue, sentence / surrender / have diarrhea

截然:

最前: / 最善: the best

sudden / immediate, rapid

urgent / sudden / hasty / rapid / fast / quick / abrupt / hurry