[单项选择]

Most worthwhile careers require some kind of specialized training. Ideally, therefore, the choice of an (31) should be made even before the choice of a curriculum in high school. Actually, (32) , most people make several job choices during their working lives, (33) because of economic and industrial changes and partly to improve their (34) . The "one perfect job" does not exist. Young people should (35) enter into a broad flexible training program that will (36) them for a field of work rather than for a single (37) . Unfortunately many young people have to make career plans (38) benefit of help from a competent vocational counselor or psychologist. Knowing (39) about the occupational world, or themselves for that matter, and then choosing their lifework on a hit-or-miss (40) , some drift from job to job. Others (41) to work in which they are unhappy and for which they are not fitted.
O
A. Therefore
B. However
C. Nevertheless
D. Moreover