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

方丝弓矫治器中控制牙齿垂直向调整的是

A．内收弯

B．外展弯

C．后倾弯

D．转矩

E．以上都不是