一对儿子?=>一对父子?
there are two people in the picture and can be figured out that they are father and son. Actually the son said that word innocently can be understood as irony his father's behaviours. Adults should form a good image in front of children. Adults drawing and scraling in the Great Wall.The Great Wall is one of the greatest wonders in this planet, it should be passed to our kids through all of our generations.Chinese were hard-working on built the Great Wall to protect ourselves, then protect it so that it won't be destoryed by the rude people now is also a part of out responsibility.