Подчеркните те эквиваленты, которые можно заменить модальными глаголами.

1. Members realized that they could get a fairer price for their oil by agreeing on how much oil to supply to the market.
2. Oil can also be extracted from unconventional sources, for example, heavy crude oil, oil sands, but production costs are high.
3. An oil spill could cause enormous damage to the environment and habitats.
4. You may have to do night shifts but that depends on your job.
5. You have to work twelve hours each day but you get breaks and time for meals.