TASK DEFINITION: You are given an English sentence with a blank, and you need to predict the missing word. After completing, the whole sentence should be gramatically correct and non-ambiguous.
PROBLEM: no one could suppose that he had been previously acquainted with or had lent himself to any of andrea's ____

SOLUTION: intrigues

PROBLEM: and although he found it rather difficult for his slower intelligence to keep ____ with her brisk mental processes

SOLUTION: up

PROBLEM: ____ have seen that the chin was very pointed and pronounced that the big eyes were full of spirit and vivacity that the mouth was sweet lipped and expressive that the forehead was broad and full in short our discerning extraordinary observer might have concluded

SOLUTION:
might