Young adults who arefit have a higher IQ and are more._________(51)to go on to university,reveals amajor new study carried out at the Sahlgrenska Academy and

Sahlgrenska University Hospital.

The results wererecently published in the Proceedings of the National Academy of Sciences（《美国国家科学院院刊》）.The study involved 2million Swedish men

doing militaryservice who were born between 1950 and 1976.

The research groupanalyzed the_________(52)of both physical and IQ tests the youngsters tookright after they started serving the army.

The study shows aclear link_________(53) good physical fitness and better results for the IQtest.The strongest links are for__________(54) thinking and verbal

comprehension.But itis only fitness that plays a________(55)in the results for the IQ test,and notstrength."Being fit means that you also have good heart and lung________

(56)and that yourbrain gets plenty of________(57),"says Michael Nilsson,professor at the Sahlgrenska Academyand chief physician at the Sahlgrenska University

Hospital."Thismay be one of the reasons_________(58) we can see a clear link with fitness,but not with muscular（肌肉的）__________(59).Weare also seeing that there

are growth factorsthat are important."

By analyzing datafor twins,the researchers have been __________(60) to determine that it isprimarily environmental factors and not genes that explain the link between

fitness anda_________(61)IQ.

"We have alsoshown that those youngsters who_________(62)their physical fitness between theages of 15 and 18 increase their cognitive performance,"says Maria

Aberg,researcher atthe Sahlgrenska Academy and physician at Aby healthcentre."This being the case,physical__________(63)is a subject that has animportant place in

schools,and is anabsolute must if we want to do well in maths and other theoretical subjects."

The researchers havealso compared the results from fitness tests _________(64)national service withthe socio-economic status of the men later in _________(65).Those

who were fit at 18were more likely to go into higher education,and many secured more qualifiedjobs._________(58)

A.what

B.why

C.how

D.where