Answer:
Friction is useful in some cases like walking and cycling ..
but it is unwanted in machines as it create unwanted sounds and heat .,due to which we loss energy
Explanation:
mark me as brainliest ❤️
Jack Kilby invented the circuit
Answer:
both
Explanation:
and I'm serious he is literally both
Answer:
true
Explanation:
with out trees we would have no air with out animals the envirounment would slowly decay