What is space junk and why do we need to know about it?

Space junk, or space debris, is any piece of machinery or debris left by humans in space. It can refer to big objects such as dead satellites that have failed or been left in orbit at the end of their mission. It can also refer to smaller things, like bits of debris or paint flecks that have fallen off a rocket.

answer; i believe that the correct answer is ; males are hemizygous for the x chromosome;

this transfer is call conjunction