Sittingstillandkeepingquietseemslikewhatstudentsshouldd...
问题详情：Sittingstillandkeepingquietseemslikewhatstudentsshoulddoinclass.However,puttingyourfeetonthetable,usingiPads,eatinganddrinkingmayalsotakeplaceinschool.Americansarefamousfortheircasual(随意的)s...