be动词用法口诀：单数is,复数are,I是am,you是are,is用作她、他、它.用be动词的正确形式填空.
1、what_______it?―It____a map.
2、_______that your jacket?―Yes,it_____.
3、________you jenny?―No,I_____not.I_______grace.
4、____she his friend?―No,she_____his sister.