On the table lies a very hard old bookmark.

2.You should not fold any pages in a library book.

3. Lately, I have been reading more nonfiction books.

4. During the week Mom is entirely too busy to read.

5. She recommends especially enjoyable books to all her friends.

adverb=adverb that it modifies

1.On=table
2.should=fold
3.lately=reading
4.during=week
5.especially=enjoyable

Only 3 and 5 are correct.

1.On=table
2.should=fold
3.lately=reading
4.during=week
5.especially=enjoyable

On = preposition
should = auxiliary verb
during = preposition