(2) Sea Level
No tough read here. The most challenging thing about The Borrowers is that it is set in a different time period, back in the olden days of the early 1900s, so you might not be familiar with such everyday items as blotting paper (1.20), or "sealing wax and hairpins and drawing pins and thimbles" (1.19).
No worries, though. There won't be a quiz (well, there might be a quiz), and knowing the exact definition of the things the family borrows doesn't really contribute anything extra special to the story itself. So enjoy the ride, and don't sweat the small stuff. Unless it's the remote.