According to economic theory, a nation should produce and export those items ( ) it gains a competitive advantage.

(单选题)( ). (单选题)( ). (单选题)( ). (单选题)( ). (单选题)Which is Amy's suggestion to the Office Mate? ( ) (单选题)What kind of problem is the Office Mate facing? ( ) (单选题)Which statement is not Amy's suggestions to the woman "Exhau (单选题)What kind of problem is the "Exhausted" facing? ( ) (单选题)Which statement is not true about the woman "Exhausted" acco (单选题)What cannot be inferred from the passage? ( )