5、oo/also变either;遇到and变or;遇到always变never。例句:1.Therearesomeboysintheclassroom.Therearen'tanyboysintheclassroom.2.Thegirlcansinganddance.Thegirlcan'tsingordance.相关练习:1.Mikewouldlikesomechicken.→Mike______like______chicken.2.He often goes to bed at ten.→Heoften___________tobedatten.3.Maryisateacher,to