【2016高考训练】阅读下列短文, 从给的四个选项 (A、B、C和D) 中, 选出最佳选项。
In the mid1950s，I was a somewhat bored earlyado lescent male student who believed that doing_any_more_than_necessary_
was_wasted_effort.One day，this approach threw me into embarrassment.
In Mrs.Totten's eighthgrade math class at Central Avenue School in Anderson，Indiana，we were learning to add and subtract decimals (小数)．
Our teacher typically assigned daily homework，which would be recited in class the following day.On most days，our grades were based on our oral answers to homework questions.
Mrs.Totten usually walked up and down the rows of desks requesting answers from student after student in the order the questions had appeared on our homework sheets.She would start either at the front or the back of the classroom and work toward the other end.
Since I was seated near the middle of about 35 students，it was easy to figure out which questions I might have to answer.This particular time，I had completed my usual two or three problems according to my calculations.
What I failed to expect was that several students were absent，which threw off my estimate.As Mrs.Totten made her way from the beginning of the class，I desperately tried to determine which math problem I would get.I tried to work it out before she got to me，but I had brain freeze and couldn't function.
