怎样将单数句改为复数句?

怎样将单数句改为复数句? 将单数句改为复数句, 将单数句改为复数句Dose the boy speak English? 将下列单数句变复数句,复数句变单数句 Are they bookcase 怎样改为单数句? 单数句变复数句,复数句变单数 改为单数句 is this your ruler? 改为复数句 Are these her erasers?改为单数句 is that your photo改为复数句 are these her borthers 改为单数句 将句子改为各种形式That is my pencil case(改为复数形式）Thoes are our pens.(改为单数形式）These are apples.(改为单数形式）She has a basketball.（改为否定句） 将下列单数句改为复数句 Is this your pencil?Is that your cousin?Where is your key?Is it on the chair?This is a dog. 英语题目(单数句改成复数句),(复数句改为单数句)this is a bus.that is a big peachthey are girlsthey are old monkeys. 单数句改为复数句The boy is going to have an English lesson. thoes boys and girls are my classmates 改为否定句还有this flower is very beautiful将名次单数改为复数急 英语的复数句改单数句 英语单数句变复数句 英语的复数句改单数句 Those are my friends怎样改为单数句?什么是单数句?