(1) Looking at the bar chart, we can see that the experimental primary school library borrowed literature books 1 10, story books 145, popular science books 36 and history books 125 last week. Story books and ordinary books are more popular with students;

(2)( 1 10+ 145+ 136+ 125)÷4

=5 16÷4

= 129 (Ben)

A: The average reading volume of these four categories last week was 129.