A couch potato:沙發土豆(整天窩在沙發里看電視的人);電視迷
His mother always warned him he'd turn into a couch potato if he watched too much TV.
他的母親總是警告他說要是看太多電視會變成沙發土豆的.

Run/take its course:(of a series of events, an illness, etc.) develop in the natural or usual way without being chanded or stopped.
(指一系列事件或疾病等)持續到自然結束,任其發展,聽其自然
The doctors agreed to let the illness run its course, rather than prescribe drugs which had little chance of success.
醫生認同此病只能順其自然,而不用那些幾乎沒有什么療效的藥.
We must allow justice to take its course.
我們必須讓正義得到伸張.