简答题Direction: Read the following excerpt from “Letter to a B student” One instructor handled us very wisely, it seems to me. On Sunday evenings in particular, he would make a point of stopping in at a local bar frequented by many of the GI-Bill students. There he would sit and drink, joke, and swap stories with men in his class, men who had but recently put away their uniforms and identities: former platoon sergeants, bomber pilots, corporals, captains, lieutenants, commanders, majors — even a lieutenant colonel, as I recall. They enjoyed his company greatly, as he theirs. The next morning he would walk into class and give these same men a test. A hard test. A test on which he usually flunked about half of them. Oddly enough, the men whom he flunked did not resent it. Nor did they resent him for shifting suddenly from a friendly gear to a coercive one. Rather, they loved him, worked harder and harder at his course as the semester moved along, and ended up with a good grasp of his subject — economics…. Please identify the following elements from the above excerpt: the topic sentence, the cause and the effect.