Hi! Ron I have a question. why B is wrong answer? I can not choose one between B and C when I was considering. The passage is primarily concerned with (A) evaluating the effect of climate on the growth of trees of different species (B) questioning the validity of a method used to study tree-ring rec...

:D Thanks a lot! By the way, I found my reading skills very weak. Sometimes, I cannot answer questions correctly even I have know the whole passage well. Can you give me some pieces of advice on reading? B is wrong because it's wrong. near the end of the passage the author describes a few cases in w...