Ответы
1. Howard started at last and reached the mountains late…
2. They had the same books at home that is why they refused to buy them.
3. The boy threw a stone at the crow and it flew away.
4. They have been working at this problem for a year.
5. She understood it at once (еще можно at last) and frowned.
6. Larry never shouts at his children and they respect him very much.
7. I did not recognize you at once.
8. We need at least three more days to finish this work.
9. My uncle said they had to do it at work.
10. They always laugh at his jokes.
11. Mankind is surprised at the size of Egyptian pyramids.
12. Liz is good at geography and at physics.
13. Pakistan was at war with India some decades ago.
14. My mother always gets up at night and does a lot of house work.
15. Hilbert was driving his Mercedes at 160 kilometers and we were scared.
16. Thomas was at work in Russia for three years.
17. Sonia is a very naughty girl but at least she is very kind-hearted.
18. At this time of the day dad is at work.