CIF价格条件下保险费的计算公式为（），

A.保险费=CIF×加成率×费率

B.保险费=CIF×费率

C.保险费=CIF×（1+加成率）

D.保险费=CIF×（1+加成率）×费率

Tom never loses heart in face of difficulties,__ ,he always tries his best to overcome them.

A．On the other hand

B．On the contrary

C．At the same time

D．As a result