Why do many female athletes fall victim to knee injuries? Rebecca L0bo，a basketball star，grabbed a rebound during the first seconds of game in June 1999．______ （1）．A pain shot from her knee and drove Lobo t0 the floor．Tests revealed that Lobo had torn her anterior cruciate （十字的，交叉的）ligament（韧带），0r ACL，resulting in the end of her play for the season．______（2） Lobo，perhaps the most recognized player in the United States，is one of a growing number of female athletes suffering ACL injuries．Experts say that female athletes in middle school，hi曲school，college and professional sports may be eight times as likely as male athletes to experience ACL injury． _______（3）．Why are so maw female athletes falling victim to ACL injuries? Spots physicians say one reason is the growing number of females involved in high—impact spots，such as soccer and basketball．Jeff Bauer，a biochemist，however，thinks bone size plays a key role．He examined the knee joints of skeletons of 200 humans who had died at an early age． Studies of the skeletons of 100 males and 100 females showed in measurement after measurement that the bones making up a female’s knee are smaller than those 0f a male of the same size．Smaller bone surfaces may lead to an increase in stress placed 0n the ACL during sharp movements．such as turning，jumping，or stopping． Bauer thinks the size difference may be the primary reason that females injure their knees more often than males do with the same amount of training and experience．“Now，that’s not bad，”add Bauer，“and it’s not good．It’s just different．” Following the knee injury，Lobo underwent surgery．_____（4）．After the surgery，the patient needs months of physical therapy to strengthen the knee muscles and ligaments．Eight months after having knee surgery．the patient still needs t0 exercise her knee every day． _____（5）．They also recommend that players do stretching exercises before a game or a practice to help keep the knees flexible and more able t0 withstand stress during play．