Ques:If exposure to cold can induce many muscle fibers to contract at once, then many muscle fibers contracting at once can be induced by?  Answer choices: - exposed genitalia  - exposure to heat  - sweating  - exposed biceps  - mechanical waves  - Electrical energy  - exposure to cold  - Veins and arteries.

Ans:exposure to cold
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Ques:If architects create structures that use energy for heating, then what is energy used for in architects' creations?  Answer choices: - energy  - warmth  - destruction  - Light  - windows  - images  - heating  - wind

Ans:heating
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Ques:If petals attract hummingbirds to the flower, then what do petals attract to the flower?  Answer choices: - pollen  - h2o  - animals  - insects  - daisies  - sunlight  - honeybees  - hummingbirds

Ans:hummingbirds
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Ques:If afirework converts chemical energy into sound, then what converts chemical energy into sound?  Answer choices: - a firework  - sensory neurons  - Gunshots  - a bottle  - a battery  - animals  - a flashlight  - engines

Ans: