8.1 1.can，can 2.must 3.should 4.May 5.Shall 6.Can 7.should 8.can
8.2 略
8.3 2.flies 3.washes 4.works 5.cries 6.teaches 7.studies 8.draws
9.picks 10.does 11.fixes 12.swims
8.4