Baby Chen weighed 6.5 lbs (2.95 kg) at birth. How much do you expect him to weigh at his first birthday?

21 or 22 pounds, babies triple their birth weight within their first year of life

This is true. yes. indeed.

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.