Astar is born when gas and dust from a nebula become so dense and hot that nuclear fusion starts. which of the following forces is responsible for the formation of a star? a. magnetism b. gravitation c. friction d. electromagnetic energy

Lymphocytes known as blastocysts make antibodies that fight infection. select the best answer from the choices provided t f

Identify the theory that can be used to explain each phenomenon. answers diffraction: wave theory interference: wave theory reflection: both particle and wave theories refraction: both particle and wave theories

I'm thinking it's 2 you are asked to explain the earth's magnetic field. which is the best reply? 1. the earth's magnetic south is similar to the north pole of a magnet. 2. the earth's core has a strong magnetic charge similar to the south pole of a magnet. 3. the earth's geomagnetic south is similar to the south pole of a magnet. 4. the earth's magnetic charge is not centered at either pole; it varies based on location.