高中英语状语从句综合单选题

Exciting as its special effects are ______, there is too much violence in the film.

A．to watch

B．to be watched

C．watching

D．being watched

How can they learn anything _____ they spend all their spare time watching television?

A．for

B．when

C．while

D．because

_____difficulty we will face, we should have confidence and try to solve it.

A．However

B．No matter how

C．Whatever

D．Whenever