Stand up,please.(改为否定句)

Stand up,please.(改为否定句) Tom,please stand up.改为否定句 stand up.(改为否定句) Stand up,please.改为同义句 Please line up.(改为否定句) Stand up,please同义句 Stand up,please.（改为反义词） Please stand up,boys and girls.(改成否定句,句意不变) stand up ,please改反问句 up,please,class,stand 连词组句 please stand up改为一般疑问句,应该怎样改? stand up,please是什么意思