1. (A) Since he speaks so rapidly, I can't follow him.
(B) If he
more slowly, I
him.
2. (A) I used my calculator, so I did not take much longer.
(B) If I
my calculator, I
much longer.
3. (A) If I hadn't been tired last night, I would have gone out.
(B) I
out because I
last night.