The answer is A, friction.
Friction is the force that resists movement, and that's why oil is used as a lubricant and why ball bearings are used for machines that need to move with very little friction(i.e. bike wheels, roller skates, fidget spinners)
Answer B is too vague
C will probably reduce efficiency greatly, but not specifically in a way that turns work into thermal energy.
D is the same as C, except that it places the blame on the person using the machine, not the machine itself.
Hope I helped clear it up for you :)
Answer:
To reduce water loss.
Explanation:
Keeping the stomata closed during the day, helps reduce water loss when dry, hot wind blows across it.
Metrology. evolution biology
Answer:
because more is being forced through
Explanation:
Answer:
both can react to form acidic compounds
