重點講解：
1. hang in there
堅持下去；別泄氣；
eg. Hang in there and you never know what you might achieve.
堅持下去，你永遠都無法預料會有什么樣的收獲。
eg. No matter how long it takes, just hang in there.
不管這事花多長時間，都要堅持下去。
2. have trouble (in) doing sth.
在…有困難；
eg. You may have trouble sleeping at night when you travel.
當你旅行時，也許你在夜晚難以入睡。
eg. A few years later, he began to have trouble walking.
幾年后，他走路也變得困難起來。
3. get used to sth.
開始習慣于；
eg. It is difficult to get used to another country's customs.
要適應另一國家的風俗習慣是很困難的。
eg. You'll get used to the climate soon.
你不久就會習慣這種氣候。