第一，迷你对话
A: Where is Peter? I haven't seen him for quite a few days.
Peter在哪里？我很多天没见到他了。
B: He's on his back now.
他卧床不起了。
A: I am sorry to hear that. But he was all right last week.
真不愿听到这个消息，但他上周还是好好的。
B: Yeah, he was caught in the rain the other day. He had got a very bad cold.
是的，那天他淋雨了，就感冒严重了。
第二，地道表达
on one's back
1. 解词释义
Be on one's back的意思是“生病卧床不起”的意思。
2. 拓展范例
E.g. He caught a bad cold and was on his back for a week.
他患重感冒，卧床一个星期。
E.g. Please give a call to our manager and tell him that I am sick and on my back.
请给一个电话给我的经理，告诉他我病得卧床不起了。
第三，视野拓展
be caught in the rain：淋雨
E.g. He was wringing wet because he was caught in the rain without an umbrella.
由于未打伞在雨中行走，他全身湿透了。
E.g. He has been caught in the rain and is wet through and through.
他遇上雨，浑身都湿透了。
E.g. I was caught in the rain on my way home. As a result I had a bad cold.
我在回家的路上遇到大雨，结果得了重感冒。
the other day：不久前某一天
She looked at the vendor who cheated her the other day with distaste.
她厌恶地望着那个前几天曾经欺骗过她的小贩。
I chanced to see our old headmaster in the street the other day.
前几天我碰巧在街上看到了我们的老校长。
get a bad cold：严重感冒
E.g. I get a bad cold; therefore, I can't attend the meeting.
我患重伤风，因此不能参加会议。
E.g. I have got a bad cold, running at the nose.
我伤风感冒很重, 直流鼻涕。