题目

Choosing the right job is probably one of the most important decisions we have to make in life, and it is frequently one of the hardest decisions we have to make. One important question that you might ask yourself is: How do I get a good job?      . There are people who can answer an insignificant advertisement in the local paper and find the best job in the world; others write to all sorts of places all over the country, and never seem to get a reply at all. Still others believe that the in-person, door-to-door approach is by far the best way to get a job; and then there are those who, t已知等差数列的前项和为，且满足，则数列的公差是（    ） A．                 B．              C．             D．