【单选题】

Most worthwhile careers require some kind of specialized training Ideally, therefore, the choice of an (21) should be made even before the choice of a curriculum in high school.Actually, (22) , most people make several job choices during their working lives, (23) because of economic and industrial changes and partly to improve (24) position. The "one perfect job" does not exist. Young people should (25) enter into a broad flexible training program that will (26) them for a field of work rather than for a single (27)

Unfortunately many young people have to make career plans (28) benefit of help from a (29) vocational counselor or psychologist. Knowing (30) about the occupational world, or themselves for that matter, they choose their lifework on a Mt-or-miss (31) . Some drift from job to joB、Others (32) to work in which they are unhappy and (33) which they are not fitteD、
One common mistake is choosing an occupation for its real or imagined prestige. Too many high-school students—or their parents for them—choose the professional field, (34) both the relatively small proportion of workers in the professions and the extremely high educational and personal (35) . The imagined or real prestige of a profession or a "white-collar" job is (36) good reason for choosing it as life’s work. (37) , these occupations are not always well paiD、 (38) a large proportion of jobs are in mechanical and manual work, the (39) of young people should give serious (40) to these fields.
A、For B、SinceC、ThoughD、As if