There are so many books!It is not easy for us to decide what to take and what to .
A. take on
B. pick up
C. leave behind
D. work out
网友回答
A. take on
B. pick up
(答案→)C. leave behind
D. work out
解析：句意为：有那么多书，很难决定如何取舍。take on表现，展现；pick up拣起，拾起；leave behind未能或忘记带某人某物,留下……；work out解决,回答出。