Answer: A) Just as.
Explanation for this question is being written.
Answer: B) When everyone has been served.
Answer: B) No sooner had he waved his hand than she turned away.
Answer: D) As soon as.
Answer: A) The next time.
Answer: A) The moment.
Answer: C) Hardly had the date of the conference been chosen when invitations were sent out.
Answer: B) The moment.
Answer: C) As