单选题 A certain packing crate contains between 50 and 60 books. How many books are there in the packing crate?
(1)If the books are counted out by three, there will be one book left over.
(2)If the books are counted out by sixes, there will be one book left over.

A、条件(1)充分，但条件(2)不充分．
B、条件(2)充分，但条件(1)不充分．
C、条件(1)和(2)单独都不充分，但条件(1)和条件(2)联合起来充分．
D、条件(1)充分，条件(2)也充分．
E、 (E) 条件(1)和条件(2)单独都不充分，条件(1)和条件(2)联合起来也不充分．

【正确答案】 B

【答案解析】[解析] 在50和60之间被3除余1的数有52，55，58三个，所以(1)不充分；在50与60之间被6除余1的数只有55，所以(2)充分。