在中国找个语伴（题目这样写也可以，但我觉得“我在中国留学时的语伴”可能更好一些）

我在中国留学的时候， 刚开始一直都没有找到合适的语伴。我发现大部分的人都在学英文，但我的母语却是德文。 直到有一天有个朋友给我介绍了一个。 聊着聊着，竟然发现她的专业刚巧是德文。终于找到了一个合适的语伴！我们当时就决定，以后要经常一起学习。为了提高彼此的外语水平，我们天天都一起做作业了，互相帮助，修改了对方的作文，等等。平时我们俩都很认真，但有时候我们并不想学习。碰到了这个情况的时候碰到这样的情况（或者“每当这个时候”），我们就一起出去玩了。这样一来，我们一起玩花的时间很快就超过了练习语言的时间。我现在回国了之后很珍惜怀念那段时间，希望我能快点回中国，再去找她，再重温那段美好的时光享受哪些天的娱乐。

emm, I'd like to choose all of you as Best Answer, but ... I have to say der frühe Vogel fängt den Wurm.

Aha, fortpflanzen is the verb, separable verb, I understand^_^

Let me explain. As a physicist, I think "middle" is usually used in one dimension. AABAA B is in the middle. "center" is usually used in two or three or even more dimension. AAAAA AABAA AAAAA B is in the center. When they are used not in physical world, but in some abstract world, it's similiar. one dimension: the middle class(income), middle school(education level), middle age(age), middle multidimension or complex concept without quantity evaluation: cultural center, scientific center, sport center, ...

Geographically, the center of the current territory is Lanzhou. Historically and culturally, the center of the China Proper is Henan province In politics, the center is Beijing. In economics, three centers: Shanghai(East), Guangzhou(South), Beijing(North). In finance, Shanghai, Beijing In scientific research, Beijing, Shanghai