内存与磁盘之间交换信息的最小单位是
A．记录
B．数据项
C．块
D．文件
参考答案：D
He was unhappy when he sold his guitar.After all,he _____it for a long time.
A．has had
B．had had
C．has
D．had
《礼记》是一部（）
A．法家著作
B．道家著作
C．墨家著作
D．儒家著作
