【正确答案】(1) Acceptance should be made by a specific offeree, the particular person or a group of persons, who is/are clearly stipulated in an offer.
   (2) An acceptance should be an unreserved assent to all the terms designated in the offer.
   (3) Acceptance should reach the offeror within the time of validity.
   (4) Acceptance should be declared by the ways stipulated in the offer, either orally or in a written form.