join 参加组织或人
He joined us in the discussion yesterday.他昨天参加了我们的讨论.
He joined the army two years ago.他两年前参军了.
take part in=join in参加活动
In early days only male athletes were allowed to take part in the Olympic Games.在奥林匹克运动会早期,只有男性运动员才能参加比赛.
attend参加会议
I shall be attending the meeting.我会参加会议.
所以选A
根据上面可以看出
attend参加会议
I shall be attending the meeting.我会参加会议.
join 参加组织或人
He joined us in the discussion yesterday.他昨天参加了我们的讨论.
答案A