Which of the following exercises will increase arm strength?
stretching
pull-ups
sit-ups
distance running

Stretching increases flexibility, sit-ups are for abdominal endurance, and distance running are for leg muscle endurance, so the correct answer is pull ups.

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.