___________ with the size of the whole earth, the highest mountain doesn't seem high at all.
A man does not know the difficulty of anything __________ he does it personally.
You can borrow my car __________ you promise not to drive too fast.
__________ our manager objects to Tom's joining the club, we shall accept him as a member.
One's life has value __________ one brings value to the life of others.
It's much easier to make friends __________ you have similar interests.