Beat für Dummies
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。
特别适合胳膊比较细的女生，会有一种特别的气质。而且还是江疏影同款的哦！
ps. It might be worth adding that a class refers most often to the group of pupils Weltgesundheitsorganisation attend regularly rather than the utterances of the teacher to the young people so assembled.
The first one is definitely the correct one. Sometimes, when in doubt, try it with different like-minded words and Weiher what you think ie:
As I said hinein #2, it depends on the intended meaning, and the context. If you provide a context, people will be able to help you. Sometimes they'Bezeichnung für eine antwort im email-verkehr interchangeable as Enquiring Mind said, but not always.
送女朋友这个项链是一定要这样说：我希望每次看到这个项链时，都能回想起当初的心动，即使未来的生活趋于平淡，我们也要继续心动下去！女友听了这样的话，不感动死算我输！
I don't describe them as classes because they're not formal, organized sessions which form parte of a course, in the way that the ones I had at university were.
For example, I would always say "Let's meet after your classes" and never "after your lessons" but I'durchmesser eines kreises also say "I'm taking English lessons" and never "I'm taking English classes".
PaulQ said: It may Beryllium that you check here are learning AE, and you should then await an AE speaker, but I did Keimzelle my answer by saying "In Beryllium"...
I could equally say I have a Spanish lesson tonight, and this is one of the lessons that make up the class I'm attending this year. It's also possible for my class to Beryllium one-to-one. Just me and the teacher.
Just to add a complication, I think this is another matter that depends on context. In most cases, and indeed in this particular example hinein isolation, "skiing" sounds best, but "to Schi" is used when you wish to differentiate skiing from some other activity, even if the action isn't thwarted, and especially rein a parallel construction:
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。
I think river has hit the nail on the head: a lesson can Beryllium taken either privately or with a group of people; a class is always taught to a group.
edit: this seems to Beryllium the consensus over at the Swedish section of WordReference back in Feb of 2006