7、tlast.A.passedB.failedC.hadD.took10用心爱心专心()20.I don’t know _________. A. what to do it B. how to do C. what to do D. to do what()21.Youdidn’thavebreakfast.You________behungrynow.A.mustB.can’tC.couldD.might()22.—Don’t______,mychildren.Keepworkingonandyouwillbesuc