Question

Which of these had not yet happened when this article was

Answer 1

Answer:

C. The seeds of sunflowers were used to make cooking oil.

Explanation:

"One way that they can make biofuel is by planting the sunflower seeds, harvesting them, taking the seeds, pressing them for their oil to create biodiesel and biofuel that could help run hybrid cars, so that people wouldn't have to use as much fuel".