Helppp m In the 1950s, the polio virus paralyzed many children for life. Today, polio has
been reduced by 99 percent. Which of the following has played the greatest
role in reducing polio infections worldwide?
A. Cooperation
B. Education
C. Agriculture
D. Consumption

the earth is thought to have been formed about 4.6 billion years ago by collisions from a cloud of hydrogen, helium, rock, ice and other materials. these were pulled together by gravity to form objects in and around earth like- asteroids and small early planets called planetesimals.

so, the best possible answer to this question will be option d- to harden materials to form different parts of earth’s layers

all these collisions do one thing, and that thing is explained in the last option. when dusst, rocks and ice collide, they harden and form giant layers of rocks or hard ice.

d)   to harden materials to form different parts of earth’s layers

hope it ,

bioteacher101