求翻译：Then, the collar 3 is presented above the base 2 by orienting the collar 3 around its longitudinal axis so that the two flat sections 8a of the tubular body 8 are positioned overhanging the flat sections 16a of the opening 16 of the flange 6 of the base 2, and the operator inserts the tubular body 8 of%2是什么意思？

待解决 悬赏分：1 - 离问题结束还有