1.After（ ）,I go to school.A.breakfast B.the breakfast C.a breakfast D.an breakfast

选A
一日三餐前不加任何冠词.
at 指时间点.如 at 8:05
in 指时间段.如 in the morning,in summer,in 2011
on 也指时间段,但是,却必须指具体的某一天或与具体某一天有关的时间段.如 on Sunday,on May 2,on the morning of June,29
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