If copper is a chemical element that is essential for body processes, then what is a chemical element that is essential for body processes? Answer choices: - Energy. - water - blood - Energy - sodium - copper - positive - ice
copper

If tobacco is harmful to lungs, then what does tobacco harm? Answer choices: - lungs - plants - cancer - cells - tissue - blood - kidney - people
lungs

If energy-saving is important when electrical energy is used to produce light, then energy-saving is important when electrical energy is used to produce what? Answer choices: - sound - a stove - crops - light - oil - motion - Heat - waves
light