What is made of a central star around which various other non-star objects orbit?
a) planetary system
b) a nebula
c) a galaxy
d) black hole

The theories on the expansion of galaxies maybe re-examined to strengthen science should not be tested to strengthen science will weaken scientific knowledge if they change will become laws if they don't change

Asea turtle has washed up on a remote section of a beach. this known as a stranding occurs when a dead, sick or injured sea turtle washed up on the shoreline. which statment best explain why stranding should be reported immediately to local authorities

About __ of the mass of the cell is water