主要問題是燃料

主要 zhuˇ yaoˋ

(Main, Mainly, Mostly, Predominantly, Primarily, Principle) Principle, Main, Mainly, Mostly, Primarily, Predominantly

主要問題 zhuˇ yaoˋ wenˋ tiˊ

(Main problem) Main problem, The main problem

問題 wenˋ tiˊ

(Concern, Concerns, Problem, Problems, Question, Questions) Question, Problem, Problems, A problem, The problem, The problems, Questions, A question, The question, The questions, Concern, Concerns, A concern, The concern, The concerns

問題是 wenˋ tiˊ shiˋ

(Issue, Question, problem is) The question is, The problem is, The issue is

燃料 ranˊ liaoˋ

(Combustibles, Combustion, Fuel) Fuel, Combustibles, Combustion material