Пишу только то, что надо вставить:
1 the most careful; us
2 was reading
3 was taken
4 children; bookshelves
5 themselves
6 were talking; came
7 first; more difficult; second
8 had travelled
9 have found; earlier
10 had lost
11 tells
12 would arrive; was expected
13 ourselves
14 biggest; them