After earthquake, ________people were homeless.
The math problem is so hard. I really don’t know________.
We played badminton ______ Sunday afternoon.
–Have you ever ________ an amusement park? --Yes, I have.I ________ Fun Times Amusement Park last year.
–Have you finished your homework yet? --Yes, I ________ it twenty minutes ago.
What a nice day! You should go sightseeing ___________ watching TV at home.