Answer the following question given this paragraph: Solar cells convert the energy in sunlight to electrical energy. Solar cells are also called photovoltaic (PV) cells because they use light ( photo- ) to produce voltage ( -voltaic ). Solar cells contain a material such as silicon that absorbs light energy. The energy knocks electrons loose so they can flow freely and produce a difference in electric potential energy, or voltage. The flow of electrons creates electric current. Solar cells have positive and negative contacts, like the terminals in chemical cells. If the contacts are connected with wire, current flows from the negative to positive contact. The Figure below and following URL show how a solar cell works. http://www. suntreksolar. com/solarElectricity/howCellsWork. asp. Q: Solar cells convert the energy in sunlight to what type of energy? Choices: - active energy - radical energy - stellar energy - electrical energy A:
electrical energy
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Answer the following question given this paragraph: After you eat and digest a sugary snack, the level of sugar in your blood quickly rises. In response, the endocrine system secretes the hormone insulin. Insulin helps cells absorb sugar from the blood. This causes the level of sugar in the blood to fall back to its normal level. Q: What hormone does the endocrine system secrete to help cells absorb blood sugar? Choices: - glucose - testosterone - Cortisol - insulin A:
insulin
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Answer the following question given this paragraph: Chemical weathering is different than mechanical weathering. The minerals in the rock change. The rock changes composition and becomes a different type of rock. Most minerals form at high pressure or high temperatures deep within Earth. But at Earth's surface, temperatures and pressures are much lower. Minerals that were stable deeper in the crust are not stable at the surface. That's why chemical weathering happens. Minerals that formed at higher temperature and pressure change into minerals that are stable at the surface. Chemical weathering is important. It starts the process of changing solid rock into soil. We need soil to grow food and create other materials we need. Chemical weathering works through chemical reactions that change the rock. Q: What type of weathering causes the minerals in a rock to change? Choices: - toxic - natural - artificial - chemical A:
chemical
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Answer the following question given this paragraph: Q: Platelets play a role in what cascade of reactions that converts plasma fibrinogen to fibrin? Choices: - hemophilia - sickle cell anemia - bleeding - blood clotting A:
blood clotting
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