填空题

For high school students, working more than 20 hours a week at a part-time job could be doing more harm than good, a new study suggests. These results (47) a number of recent studies that found no negative effects on students from working intensive hours, but researchers say that the (48) of their data, using advanced statistical measure, may account for this difference.
According to the study, students who worked more than 20 hours a week had lower (49) for educational attainment, lower school engagement, higher levels of substance abuse, and other problem behavior. However, these same students also showed more autonomous(自主) decision-making and had (50) higher grade point averages than teens without jobs.
Additionally, students who worked long hours still (51) negative outcomes up to a year after quitting or reducing hours; researchers advise that working long hours for a year or more of high school could have even greater (52) effects. This doesn’t mean that high school students shouldn’t work at all, and in today’s economic environment, many need to work part-time to help their families or (53) for college.
Researchers note that parents, educators and employers should be (54) to allow adolescents to work lots of extra hours during the school year. "It’s a small difference—it won’t turn you into a felon (罪犯) (55) , but it does have significant impacts in (56) of academic engagement, academic outcomes, drug use and delinquency(青少年犯罪)."
A. bold
B. cautious
C. compete
D. contradict
E. expectations
F. experienced
G. frustrated
H) negative
I) occasionally
J) overnight
K) save
L)slightly
M) supplement
N) terms
O) treatment