Выберите верный вариант и объясните: 1. The company a) designsor b)

Изберите верный вариант и объясните:
1. The company a) designsor b) is designing websites.
2. Many companies a) set up or b) are setting up Swedish operations because Sweden is attractive for business investment.
3. Sam is in the office working on his computer. At this time yesterday, he a) worked or b) was also working on his computer.