Which of the following must be true in order for an object to stay in place?

a) the forces must be balanced.

b) the forces must be positive.

c) the forces must be negative.

d)the forces must be gravitational.

Is this a single replacement reaction or there is no

There is one girl i like and i don't know how to tell her that, i have a feeling she knows but if she doesn't i don't want to make a fool out of myself how is one way to boost my confidence on asking her out

How do dying stars contribute to the formation of planets