Answer:
they r schooling fish
Explanation:
they need to be kept in groups of 5.
solid
Explanation:
because it has a definite shape and volume
It is a theory on a show that people try to solve.
Answer:
A system of two co-axial cylindersof different diameters which rotate together is called wheel and axle example; the door knob , knob of the tap ,screw driver,water tap
