Why is oil considered a strategic commodity?

Food can come from sustainable or unsustainable resources. why has the united nations suggested that bugs could be a better source of food than animals like pigs or cattle?

Which statement about portugal is not true? a. it granted independence to its last colony in 1975 b. it has avoided conflict with spain c. it was a leader in european world exploration in the 1400s d. its economy is changing from agricultural to industrial b. it has avoided conflict with spain

The process by which liquid water changes into water vapour is called what ?