Answer the following question given this paragraph: In the liquid state, the hydrogen bonds of water can break and reform as the molecules flow from one place to another. When water is cooled, the molecules begin to slow down. Eventually, when water is frozen to ice, the hydrogen bonds become permanent and form a very specific network (see Figure below ). Q: As the temperature of water decreases what happens to the speed of the water molecules? A:
OPTIONS:
- move faster
- evaporate
- begin to boil
- slow down

Answer: slow down

Answer the following question given this paragraph: A nerve impulse begins when a neuron receives a chemical stimulus. The impulse travels down the axon membrane as an electrical action potential to the axon terminal. The axon terminal releases neurotransmitters that carry the nerve impulse to the next cell. Q: What begins when a neuron receives a chemical stimulus? A:
OPTIONS:
- a induce impulse
- a metabolism impulse
- nerve reaction
- a nerve impulse

Answer: a nerve impulse

Answer the following question given this paragraph: Viruses were assumed to exist before they were first seen with an electron microscope in the 1930s. Multiple hypotheses for viral origins have been proposed. Q: Viruses were assumed to exist before they were first seen with an electron microscope in which decade? A:
OPTIONS:
- 1960's
- 1890's
- 1940's
- 1930 ' s

Answer:
1930 ' s