It did so because the substantial increase in the membership of the United Nations, especially in terms of developing countries, as well as the changes in international relations, necessitated a review of the composition of the Security Council.
大会这样做是因为联合国成员数量有了大幅度增长，特别是发展中国家的数量，并且国际关系也有改变，必须对安全理事会的组成进行审查。