NOT all that Mrs. Bennet, however, with the assistance of her five daughters, could ask on the subject was sufficient to draw from her husband any satisfactory description of Mr. Bingley. They attacked him in various ways; with barefaced questions, ingenious suppositions, and distant surmises; but he eluded the skill of them all; and they were at last obliged to accept the second-hand intelligence of their neighbour Lady Lucas. Her report was highly favourable. Sir William had been delighted with him. He was quite young, wonderfully handsome, extremely agreeable, and, to crown the whole, he meant to be at the next assembly with a large party. Nothing could be more delightful! To be fond of dancing was a certain step towards falling in love; and very lively hopes of Mr. Bingley's heart were entertained.

第一句 NOT all that Mrs. Bennet, however, with the assistance of her five daughters, could ask on the subject was sufficient to draw from her husband any satisfactory description of Mr. Bingley.

请教老师， was sufficient 前是否有一个关系代词which或that省略了？为什么可以省略呢？

麻烦老师分析一整句的结构成分，谢谢！