Problem:OPTIONS:
- cigarettes
- Malnutrition
- burning coal
- Healthy food
- Exercise
- Good health
- Allergies
- Pesticides

You are presented with the quiz "What can cause the immune system to not work properly?" But you don't know the answer, so you turn to your teacher to ask for hints. He says that "immunodeficiency occurs when the immune system is not working properly" and "malnutrition , particularly with lack of protein , can cause acquired immunodeficiency". So, what's the best answer to the question?
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A: Malnutrition

Problem:OPTIONS:
- after too much water received
- scarce resources
- nonliving organic matter
- mammals
- Something made from fermented ricce
- large animals
- birds
- harmful substances

You are presented with the quiz "Most animals that live on rocky shores eat what?" But you don't know the answer, so you turn to your teacher to ask for hints. He says that "bivalves feed on plankton and nonliving organic matter" and "most animals that live on rocky shores eat plankton". So, what's the best answer to the question?
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A: nonliving organic matter

Problem:OPTIONS:
- movement
- warmth
- photons
- sunlight
- motion
- sun's heat
- dangerous
- Heart rate

You are presented with the quiz "A light bulb emits what when turned on?" But you don't know the answer, so you turn to your teacher to ask for hints. He says that "alight bulb converts electrical energy into light energy when it is turned on" and "aphoton is a packet of light energy". So, what's the best answer to the question?
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A: photons

Problem:OPTIONS:
- Physical weathering
- Something to move
- destroying life
- It expands
- Greenhouse gases
- contamination
- Pollution
- harmful substances

You are presented with the quiz "creating paper may cause" But you don't know the answer, so you turn to your teacher to ask for hints. He says that "creating paper requires cutting down trees" and "to cut down a tree is like destroying a life". So, what's the best answer to the question?
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A:
destroying life