做題水平和幹勁更高大。研究 ABC有很厲害，研一10 paper。我孩子0

Most O level abc go to wall street. Percentage of O level abc difinitely less than foreign students. 

Most start research right away. some 9 to 5 from day 1, going to classes is just break. My kid goes to quite a few research group meetings a week just to get a feel of group culture and research subject. Some schools like Harvard don't even have PhD qualifying exams. Some schools only require a couple of classes in total. 

Daily conversation with almost no accent is still lower than native speaker. Image one needs to read say 10-15 papers and try to get main idea behind those papers and which could be a good one to dive into.