Which of these are the largest? (science)

a. meteoroids
b. asteroids
c. all are the same size
d. comets

Which is special about a dc circuit ? a. it has both series and parallel components b. it has only series or only parallel components c. charge moves in a single direction d. charge moves back and forth quickly

The dot diagram represents the motion of the motorcycle as it moves from left to right

A100-watt light bulb illuminates a solar cell. the electricity from the solar cell operates a water pump that delivers 1 watt of power. what is the efficiency of the system?