In March he goes on a survival course and learns about the “umbles”: as hypothermia sets in you mumble, fumble, grumble, stumble, then finally tumble.

三月，开始野外生，懂得了寒冷下嘴、脚是么样：低温开始了，咕哝，，囔，踉跄，终于仆倒在地。