Answer the following question given this paragraph: The gas giants are mostly made of hydrogen and helium. These are the same elements that make up most of the Sun. Astronomers think that most of the nebula was hydrogen and helium. The inner planets lost these very light gases. Their gravity was too low to keep them and they floated away into space. The Sun and the outer planets had enough gravity to keep the hydrogen and helium. Q: What are the gas giants mostly made of . Choices: - calcium and helium - nitrogen and helium - hydrogen and carbon - hydrogen and helium A:
hydrogen and helium
(Question)
Answer the following question given this paragraph: Radioactive decay is the breakdown of unstable isotopes into stable elements. For example, carbon-14 is an unstable isotope of carbon that decays to the stable element nitrogen-14. The rate of decay of an isotope is measured in half-lives. A half-life is the time it takes for half a given amount of an isotope to decay. Q: What is the term for the breakdown of unstable isotopes into stable elements? Choices: - isotopic decay - radioactive decrease - secondary decay - radioactive decay A:
(Answer)
radioactive decay
Ques: Answer the following question given this paragraph: Why do satellites stay in orbit? Why don't they crash into Earth due to the planet's gravity? Newton's law of universal gravitation describes what happens. Every object in the universe is attracted to every other object. Gravity makes an apple fall to the ground. Gravity also keeps you from floating away into the sky. Gravity holds the Moon in orbit around Earth. It keeps Earth in orbit around the Sun. Q: What keeps earth in orbit around the sun? Choices: - energy - motion - momentum - gravity A:
Ans: gravity
(Q).
Answer the following question given this paragraph: Volcanoes and earthquakes are common at active margins. Active margins are near plate boundaries. Q: What are two common weather characteristics of hurricanes? Choices: - low winds and sandstorms - high winds and snowfall - small winds and rainfall - high winds and rainfall A:
(A).
high winds and rainfall
Ques:Answer the following question given this paragraph: 34.3 Vertebrates are craniates that have a backbone. Q: What type of craniates have backbones? Choices: - juveniles - invertebrates - larva - vertebrates A:

Ans:vertebrates
Answer the following question given this paragraph: There is some variation in the inherited traits of organisms within a species. Without this variation, natural selection would not be possible. Q: What process would be impossible without some variation in the inherited traits of organisms within a species? Choices: - environmental selection - darwin's selection - characteristic selection - natural selection A:
natural selection