The author's age is probably ______.……

单项选择题In Para. 4, the auther portrays himself as ______.

单项选择题Although the author says I am here to teach, his purpose is really ______.

单项选择题The best title for this passage would be ______.

单项选择题The author's tone in this passage is ______.

单项选择题Owing to cultural ethnocentrism, people may ______.