公安机关任务，是指公安机关在国家法律所确定的管辖范围内，为实现一定的目标而进行所承担的工作内容。 ( )
参考答案：对
—Have you graduated from college?
—Yes, ________.
A．I studied French for two years.
B．I have been studying French.
C．I have studied French for two years.
D．I had studied French for two years.
市场像一只看不见的手，使各种资源按供求关系的变化在各行各业之间的流动达到较好的配置。这个比喻说明（ ）
A．市场是看不见、摸不着的
B．市场决定供求关系
C．市场经济是一种有效的资源配置方式
D．市场经济可以保证供需平衡
