1.C 微粒，颗粒，粒子 a very small piece 2.C 极少量 smallest possible amount 3.C 小品词 any of a number of usually short words that are not as important in a sentence as the subject, verb, etc.
Alpha-rays consist of alpha particles.α射线是由α粒子构成的。 There are particles of dust in the air.空气中有尘粒。 There's not a particle of truth in her story.她讲的没有一句实话。 Prepositions and conjunctions are particles.介词和连词是小品词。