7. Закончите следующие предложения, используя текст.

1. This latter stage comes after the studies of structural geology…

2. However, in an underground oil reservoir the proportions of gas, liquid, and solid depend on…

3. The proportion of light hydrocarbons in the petroleum mixture varies greatly…

4. The exact molecular composition varies widely from formation to formation…

5. In the reservoir it is usually found in association with natural gas…

6. Because heavier crude oils have too much carbon and not enough hydrogen…