The world is changing fast.I strongly believe that one will easily fall behind _______ he keeps on learning.
. ___________ in the sports world, a sportsman needs to train constantly to keep himself in best condition.
. Listen, Mike. She ________________ have done it. She's been with me at the shop all day.
. —Do you want to go to the cinema tonight? —Sorry, I’m so tired. I ___________ an early night.
. With age, the mineral content of human bones decreases, ________ them more fragile.
. Let's go a little faster, ______________ we'll never get there on time.