How much is the ticket to Central Park—A one-way ticket $40, and you can another $20 for a round-trip.

The math problem is too difficult ,I can’t__________ .

I didn’t know _______________.

They offered a lot of useful information for your report; I can understand how ________ you must be feeling to them now.

, don’t waste any time and there’s only 25minutes left before the train leaves.— Don’t worry, mum. I think I can ______ it.