It is not idiomatic "to give" a class. A class, in this sense, is a collective noun for all the pupils/ the described group of pupils. "Our class went to the zoo."
By extension, a "thing that makes you go hmm" is something or someone which inspires that state of absorption, hesitation, doubt or perplexity in oneself or others.
知乎，让每一次点击都充满意义 —— 欢迎来到知乎，发现问题背后的世界。
If the company he works for offers organized German classes, then we can say He sometimes stays at the office after work for his German class. After the class he goes home.
知乎，让每一次点击都充满意义 —— 欢迎来到知乎，发现问题背后的世界。
The point is that after reading the whole Postalisch I still don't know what is the meaning of the sentence. Although there were quite a few people posting about the doubt between "dig hinein" or "digging", etc, etc, I guess that we, non natives still don't have a clue of what the Tatsächlich meaning is.
The first one is definitely the correct one. Sometimes, when hinein doubt, try it with different like-minded words and Teich what you think ie:
知乎，让每一次点击都充满意义 —— 欢迎来到知乎，发现问题背后的世界。
No, this doesn't sound appropriate either. I'm not sure if you mean you want to ask someone to dance with you, or if you're just suggesting to someone that he/she should dance. Which do you mean?
He said that his teacher used it as an example to describe foreign countries that people would like to go on a vacation to. That this phrase is another informal way for "intrigue."
Chillen ist ein Wort, website das in der modernen Umgangssprache vorherrschend ist des weiteren aus dem Englischen stammt. Unberührt bedeutete „chill“ auf Englische sprache so viel in der art von „kalt“ oder „kühlen“.
Just to add a complication, I think this is another matter that depends on context. Hinein most cases, and indeed in this particular example rein isolation, "skiing" sounds best, but "to ski" is used when you wish to differentiate skiing from some other activity, even if the action isn't thwarted, and especially in a parallel construction:
Wie ich die Nachrichten in dem Radioapparat hörte, lief es mir kalt den Rücken hinunter. When I heard the news on the Radiogerät, a chill ran down my spine. Born: Tatoeba
Hinein an attempt to paraphrase, I'd pop rein a "wow": I like exploring new areas. Things I never imagined I'd take any interest rein. Things that make you go "wow".