高中英语状语从句综合单选题

__________hard you try, it is difficult to lose weight without cutting down the amount you eat.
A   Whatever        B Whichever          C However         D Whenever

How I wish we studied ________there are fewer exams .

A．which

B．that

C．where

D．when

We are in a difficult position in____ we have nobody properly qualified for this work.

A．that

B．when

C．what

D．where

I have been keeping the portrait _____ I can see it every day, as it always reminds me of my childhood in Paris.

A．since

B．where

C．as

D．if