The reason grooves are rifled into the bore of a gun is so that a: bullet will be made to spin and hence have a true and accurate course on leaving the barrel. bullet moving through will have unique striations. manufacturer can put its unique mark on its product. bullet will be reduced in size before it exits the gun ballistics examiner will have an easier time identifying evidence

representative si the final answer! : )

causes

fossil fuels burn

cities become more industrialized

human population grows worldwide

the answer is the first electromagnet (a). this is because it has more coils around the ferromagnetic material. increasing the number of coils increases the surface area in which the metal interacts with the current in the coil. this enables more atoms in the metal to become aligned hence becoming more magnetized.