Ninety percent of the sun is composed of which element?
a. iron
b. helium
c. carbon
d. hydrogen

What acceleration is produced when a 3,000-n force acts on a 1,200-kg car? ignore the friction

Does water only take one path through the water cycle? (15 points)

Which of the following best describes the purpose of a nation’s boundaries? a. to limit the movement of goods and people b. to make it easier for cartographers to create maps c. to make the movement of goods and people easier d. to prevent other countries from invading territory