USAAAO 2015, I кръг — Задача 14
USAAAO First Round 2015
Условие
On the main sequence, stars obtain their energy
a. from chemical reactions.
b. from gravitational contraction.
c. by converting hydrogen to helium.
d. by converting helium to carbon, nitrogen, and oxygen.
e. from nuclear fission.
Отговори
- c
Решение
Answer: c
Оригинал в Архива: 2015-first-round-exam.pdf · официални решения: 2015-first-round-solutions.pdf