That is the problem with the random exercises: We do not have a chance to consult the notes before doing the tasks. As a random exercise these sentences are useless for me because I do not remember the rules and I am unable to deduce them from 20 examples. The only benefit is that now I know that I have forgotten all the rules about demonstrative pronouns, so now I can look up the concerning lesson, study the notes and redo the exercise. A link from the random exercises to the notes would save a lot of useless work.
I open the notes in a 2nd window. Still no help though as they are so incomplete!
I think you use "acești" if it is followed by the noun it refers to and "aceștia" if there is no noun straight after it.
I agree. Seeing all the words we would learn prior to starting a lesson helped a lot better. I would see where I learned these new worss and easily write them down and translate. Now I have to write the words as I do the lesson which really slows me down.
I don't think men is a very correct translation when speaking of specific "oameni".
People is better. After all, there could be women in that group as well, and you'd say it the same way.
IIRC it's to do with whether it's placed before or after the noun. So it would be "oamenii aceștia" (I believe it has to use the definite article with the post-noun form) or "acești oameni" (and this form requires the indefinite article for the noun) and both mean "these men/people".