Question

【题目】他们相识许多年了。 (each other)

Answer 1

【答案】They have known each other for many years.
【解析】根据句意可知句子的时态要用现在完成时，have done, 主语是they, 谓语动词要用复数，相识：know each other, 许多年：many years, for+段时间和现在完成时连用，所以答案是They have known each other for many years.