The old man leads ______happy life now, but he will never forget ______hard time when he was poor.

A．the, a

B．/; the

C．the; /

D．a, the

《服务贸易总协定》敦促世界贸易组织成员方承认其他成员方服务提供者所具有的学历或其他资格。资格要求应尽可能地以（）为基础。