When you’re unfamiliar with a situation, you might not always know this: the ins and outs.
当你不熟悉某种情况时，你可能并不总是知道这一点: the ins and outs.
这里的ins and outs可不是指进进出出，下面我们根据对话来理解这个短语吧：
对话理解：
A: when do you leave for Munich?
A: 你什么时候去慕尼黑?
B: Next Wednesday. I have a friend there who knows all the ins and outs of the city.
B: 下个星期三。我有一个朋友在那里，他知道这个城市的所有细节。
A: It’s always a good ides to have a guide who knows the ins and outs of a new city…where you could get lots for days…
A: 有一个知道一个新城市的里里外外的导游总是个好主意，在那里你可以玩多很多天……
A: Anyway, I can’t wait to eat all the best food, see all the best museums and most importantly… and find the best karaoke places.
A: 总之，我能最快吃到所有最好的食物，看所有最好的博物馆，最重要的是……找到最好的卡拉ok场所。
总结：
”To know the ins and outs of something means you are very familiar with the details of something.
‘To know the in and out of something’意思是你非常熟悉某事的细节。
The phrase ‘ins and outs’ comes from the possible dangerous twists turns in a road or path.
短语“ins and outs”来自于道路上可能出现的危险或转折。
ins and outs [ɪnz,aʊts] n.本末;底细;曲折转弯地形等有形的特色，细节;底子
举个例子：
1
I don't know the ins and outs of the matter.
我不知道这件事的来龙去脉。
2
Do you know the ins and outs of the job?
你知道这份工作的详细内容吗？
3
Miss Dakar: Let me tell you the ins and outs of our school.
达卡：让我来告诉你有关这间学校的一切。
