1. This time only the members of Group One can answer the questions.

2. This time only the memvers in Group One can answer the questions.

(Which preposition should I use? Can we use both prepositions? Which one is commonly used?)

3. Group One members only can answer the questions.

4. Only Group One members can answer the questions.
(Are both correct?)

5. The other groups should be quiet and later they can answer other questions. OK, now move on the Group Two. If you want to answer the questions, raise your hand. Don't say the answers if you are not pointed to. Got it?
(Would you check the passage as well? Thank you.)

1 and 2 -- both prepositions are correct.

3 and 4 -- both are correct.

5 -- correct.

1. Both prepositions "of" and "in" can be used in this context, but "of" is more commonly used. So, you can say, "This time only the members of Group One can answer the questions."

2. The correct preposition to use in this sentence is "in." So, you should say, "This time only the members in Group One can answer the questions."

3. Both sentences are grammatically correct, but the more common and natural way to phrase it is, "Only Group One members can answer the questions."

4. Again, both sentences are correct, but "Only Group One members can answer the questions" is more commonly used and sounds more natural.

5. The passage you provided is mostly correct. Here is a slightly revised version: "The other groups should remain quiet for now, and Group Two can answer the questions later. If you want to answer the questions, please raise your hand. Only speak the answers if you are specifically pointed to. Understood?"