Lily has been in love with Tom ___ since she met him last year.

-- Do you think it's a good idea to make friends with your students?-- ______, I do. I think it's a great idea.

Polar bears live_______ on sea ice，which they use as a platform for hunting seals

The Internet has brought _____ big changes in the way we work．

---What can I do for you？---Well，I’m afraid the box is heavy for you，but thank you all the same．