Help me. Very urgent

What is the role of lenses in microscopy?

If an electric circuit is not grounded it is best to reach out and touch it to provide the ground a.true or b.false

1which body contains the majority of the mass in the solar system earth jupiter the moon the sun 2 what keeps the objects in the solar system such as planets orbiting around the sun the force of gravity the galaxy exerts on all objects within it including the solar system the great distance between the sun and the planets the sun's nuclear fusion which acts on each object the gravitational force between the sun and each object in the solar system