5、oftimelastSunday.Havethemaskandansweraboutwhattheywerereallydoing. Explaintheword:PE,chemistry,sweep Step4Practice Showthestudentsthepictureandsay:OneSundaymorningthemanupstairsheardthesoundofchildrenplayinginthepark.Whatdidheseewhenhelookedoutofhiswindow. N