Dear Ms.Sue, thank you for your answer. Will you please help me with several more sentences which I made up but I'm not sure they are natural.

Question

1)He's got a lot of experience and knowledge, which is undoubtedly to be applied in practice.
2)His classes that I was present at were just great.
3) In the summer, I'm going away on vacation. (I mean, is the word order here OK?)
Thank you very, very much.

Answer 1

1) . . . which he will undoubtedly put into practice.

2) His classes that I attended were just great.

3) is good!