https://online2.tingclass.net/lesson/shi0529/0009/9907/174.mp3
https://image.tingclass.net/statics/js/2012
講解文本：
back to the wall 走投無路，陷入困境
Quite a few times, I had my back to the wall.
有好幾次，我都陷入了絕境。
They had to fight with their back to the wall.
他們不得不背水一戰(zhàn)。
瘋狂練習(xí)吧!
