1.I am exhausted. I shouldn't have stayed up playing PC games last night.
2.I don't know Helen very well, but we go for an occasional dinner together./but we occasionally have dinner together.
3.We are supposed to pick her up at the airport.
4.You could clearly see people drowning, but you took no action to save them.
5.Including weekends, there are only 15 more days to buy Spring Festival presents.
6.Without immediate actions, many kinds of wild animals would die from hunger.
7.That song always reminded her of the night spent in Chicago.
8.There happened to be an old man on the corner, so I asked him the way.
9.All flights to New York today are delayed because of the terrible/bad weather.
10.Whoever is responsible/Anybody who is responsible will have to pay for the damage.