单项选择题
A．ignorant B．unconscious C．conscious D．informed
A.using the same frequency while talking B.keeping the same friendly relationship as other people do C.having similar ideas, beliefs, attitudes and interests D.having the same background
A.it is not easy to have a friendly relationship with people when there is a marked difference in age and background B.the degree of friendship between two people and the reason for their shared interest can vary greatly C.friends need to know all these things D.these are the most important factors to make friends