back to back contract ,一直搞不太明白

back to back contract ,一直搞不太明白 back to back ordering the back to back Back to back back-to-back Back to Signing the contract and sending it back to you is no proble 英语翻译Flex your abs to protect your back and contract the hip back to back classrooms是什么意思 back back to shanghai.back shanghai哪个对 stand back to back翻译一下