Ahuman's most rapid growth, both physically and mentally, occurs between a0 and a1 years old. i cant figure it out and i dont know what are suppost to be in the blanks so plz

Well, l think that some effective communication is, emotional barriers and lack of attention, interest distraction or irrelevance. also some physical disabilities such as hearing problems or speech difficulties.      l hope i am correct  and you good luck.

Stimulants speed up the central nervous system.