Are they birds?改单数句

Are they birds?改单数句 they are good friends 改单数句 they are my friends改单数句 they are offices.怎样改单数句 你好、Are they student 改为单数句怎么改? They are some good dictionaries.改为单数句怎么改 把they are boxes.改为单数句怎么改 They are my old friends.(改单数句）______________________________. They are waitresses.(改单数句) ____ is a waitresses. They are orange schoolbag改为单数句,怎么改啊! These are eggs.They are small and white.改单数句 they are some apples 改单数：---------- ------------- --------------- they're or anges改单数句 What are they?They are buses改位单数形式 改单数句子They are English books.(改为单数句)It ＿ ＿ English book.横线内各填一个单词 these toothbrushes are new.改单数句 These are my horses改单数句 Those brushes are theirs.(改单数句)