I was afraid__________to my customers because I was afraid__________them.

A．of talking back；to lose

B．of talking back；of losing

C．to talk back；to lose

D．to talk back；of losing

I have been trying my best to study English          I want to have a chance to be a volunteer for the London Olympic Games.[ ]

A.but      

B.so      

C.because      

D.until