Ex201 C2 I have should be has3 I is should be are4 C5 C6 I have should be has7 I have should be has8 C9 I are should be is10 CEx21 1 C2 I was should be were3 I is should be are4 I are should be is5 C6 C7 I was should be were8 I was not changed should be were not changed9 C10 CEx22 1 C2 I is shoould be are3 I is shoould be are4 C5 I do shold be does6 I was so many should be were so many7 I has should be have8 I have should be has9 C10 I was shold be wereEx23 1 I admire should be admires2 C3 I were should be was4 I are should be is5 C6 I teke should be takes7 C8 I are should be is9 C10 I have should be hasEx20-23 1 I has should be have2 I was should be were3 I have should be has4 C5 I was should be were6 I have should be has7 C8 I have should be has9 I does should be do10 I have should be hasTOEFL Ex1 B2 D3 B4 A5 C6 C7 D8 A9 B10 BTOEFL Review test1 A2 C3 C4 C5 B6 C7 B8 A9 A10 B