which is correct? I had walked for two hours before I felt tired or I walked for two hours before I felt tired.

I had walked for two hours before I felt tired.

Explanation:

The "had" is used to show that two events took place but one started and finished before the other took place.

i think its d.

hope it you!

some attention getter quotes to support your thesis regarding brain work could be the following: :

a. storage capacity of your brain is virtually unlimited.

b. your brain produces sufficient electricity to light-up a small bulb.

c. different brain circuits are involved with reading aloud or silently.

d. your brain by itself does not feel pain.

e. reading allows your brain to download info directly.

f. brains of two musicians performing together can synchronize.