It’s rather difficult to make friends with him, but his friendship          , is more true than any other’s.

A．once gained      B．when to gain    C．after gaining     D．while gaining

It is rather difficult to make friends with him,but his friendship, ______,is more true than any other’s.

A.once gained                             B.when to gain

C.after gaining                                   D.while gaining

It is rather difficult to make friends with him,but his friendship, ______,is more true than any other’s.

A.once gained                             B.when to gain

C.after gaining                                   D.while gaining

It is rather difficult to make friends with him, but his friendship,      is more true than any other’s.

A. once gained    B. when to gain    C. after gaining    D. while gaining