Answer: A bike
A bike is composed of various simple machines. It has a wheel and axle as one component, and it also has screws to hold the various parts together, along with levers and pulleys that are connected to the pedals. So all of these simple machine concepts work together to help transport the rider from point A to point B.
The other answer choices of screw, inclined plane, and lever, are fairly simple machines that don't have many things going on at once compared to a bike.
Answer:(3)
Explanation: 2Al+3H2SO4----->Al(2SO4)3+3H2
What do you need help on?
Chemical reaction is the basis of life for living organisms; no organism can remain alive without the occurrence of chemical reactions.
Chemical reactions that occur in the living organisms are called biochemical reactions, these reactions are needed for the organism to grow, develop, survive and remain alive; when the chemical reactions stop the organism die.
For instance, to remain alive one has to eat. The food eaten can not be useful to the body if the digestive enzymes do not carry out chemical reactions on it and convert it to a form that can easily enter the blood where it is needed.