spontaneously

ad. 自发地(自生地,自然产生地,自然地,天然地)

Spontaneously igniting in air.

自燃的在空气中自发地燃烧的

I had never been spontaneously approached by a publisher and such condescension rather turned my head.

还从没有一个出版商主动来与我接洽，这种屈尊有点让我受宠若惊。