I don’t think it easy, even if we work hard, ______ the South Korea and the North Korea to sit down to talk at present.

A．persuaded

B．to persuade

C．persuade

D．persuading

可导致牙龈增生的药物不包括（）。

A.环孢素

B.苯妥英钠

C.心痛定

D.硝苯地平

E.布洛芬