Checking exercise 3 (first 5 sentences).
1. (+) _____________ (they - to swim) to the other side of the swimming pool.
2. (?) ___________ (you - to forget) to lock the door last night?
3. (+) ___________(the company - to purchase) a new building for $750,000.
5. (-) I'm sorry, _________ (I - not - to hear) you.