15. What is one problem that must be overcome before nuclear fusion reactions that produce energy on our planet are a reality? a. Scientists must determine how to control the reaction
b. A company must first apply for a patent
c. Cars have to be redesigned
d. There is not enough open space available in the United States

Particle exchange energy though elastic collision , hope this .

Read the sentences below in 1962, i tried to enroll as the first black student at the university of mississippi. the governor of mississippi blocked my entrance which best describes the verbs used in the sentences? o they are past tense verbs, which are often used in narrative essays o they are past tense verbs, which are not often used in narrative essays. o they are future tense verbs, which are often used in narrative essays o they are future tense verbs, which are not often used in narrative essays.