With a purposeful or sincere intent:正经的：带有认真或坚定的目的的：settled down to study in earnest for the examination.坚定决心认真坐下来复习准备考试
Serious; determined:坚定不移的；严肃的："Both sides are deeply in earnest, with passions that approximate those of civil war"(Conor Cruise O'Brien)“双方都很坚决认真，象是鼓足劲要打一场内战”(康纳·克鲁斯·奥布赖恩)