He/She/It isWe/They/YouareIam单数复数我用am,你用are,is 用在他她它,复数全用aream/is 的过去式是are 的过去式是waswere一、用be(is,am,are) 动词的适当形式填空。1 )I_aboy._youaboy?No,I_not.2 )Thegirl_Jackssister.3 )Thedog_tallandfat.4 )Themanwithbigeyes_ateacher.5 )_yourbrotherintheclassroom?6 )How_yourfather?7 )MikeandLiuTao_atschool.8 )Whosedress_this?9 )Whosesocks_they?his.10 )Who_I?IsAre amisisamisareisareamis11 )Thejeans_onthedesk.12 )Here_ascarfforyou.13 )Here_somesweatersforyou.14 )Theblackgloves_forSuYang.15 )Thispairofgloves_forYang