Q: Q: What type of muscle makes up most of the heart? Read this paragraph and choose the correct option from the provided answers: The heart is a muscular organ in the chest that consists mainly of cardiac muscle. It pumps blood through blood vessels by repeated, rhythmic contractions. Blood flows through four chambers of the heart when it beats. Heartbeat is controlled by electrical signals from special cells within the heart called the pacemaker. Choices: - chest muscles - heart muscle - respiratory muscle - cardiac muscle A:
A: cardiac muscle

Q: Q: What force holds together both types of star clusters? Read this paragraph and choose the correct option from the provided answers: Star clusters are small groups of stars. A star cluster is smaller than a galaxy. There are two main types, open clusters and globular clusters. Both types are held together by gravity. Choices: - weight - magnetism - inertia - gravity A:
A: gravity

Q: Q: When did we learn there was a hole in the ozone layer? Read this paragraph and choose the correct option from the provided answers: Ozone near the ground harms human health. Ground-level ozone is a pollutant. But the ozone layer in the stratosphere protects us from harmful solar rays. That's why people were alarmed in the 1980s to learn that there was a hole in the ozone layer. Choices: - 1950s - 1970s - 1990's - 1980s A:
A: 1980s

Q: Q: What do glands in the skin produce to cool down the body? Read this paragraph and choose the correct option from the provided answers: glands in the skin that produce sweat, a salty fluid that helps cool down the body. Choices: - lactic acid - saliva - mucus - sweat A:
A: sweat