2.8与4的积，减去6.5除以5的商，差是多少？
2.8×4-6.5÷5
=11.2-1.3，
=9.9．
答：差是9.9．
使用信用卡可以集存款、取款、消费、结算、查询为一体。[ ]
Mother was satisfied to see her son well _____ for the coming examinations.
A．prepare
B．prepared
C．preparing
D．to prepare
