【Asweknow，oneofthegreatchallengesforstudentsistakingtests．Thestudentsmustdowellinthetesttoadvance（进步）．Astudentwhohitsthebooksspendslonghourspreparingforatest．Studentsreadalltheirbookscarefully】

　　As we know，one of the great challenges for students is taking tests．The students must do well in the test to advance（进步）．A student who hitsthebooks spends long hours preparing for a test．

　　Students read all their books carefully，and they make sure they know all the materials the teacher has offered and prepared for every possible question．They study every night．They are“hitting the books“．In the United-States，most children begin-attending school when they are five years old．Public education is free and most children go to schools near their homes．School life in these early years is fun．The children learn to read and write．But they also play games and go on trips．There is no reason for them to hit the books at such an early age．

　　This situation changes as children grow older．The subjects become more and more difficult．Students must learn about world history，geography，and the life sciences，Tests become more common．Pressure is growing to hit the hooks and advance：However，most students really begin hitting the books for long hours only when they reach high school．High school students who hope to go to college or university must take a Special test called SAT．A high school student who gets a high score in the test has a good chance to enter a top American college．For this reason，many students hit the books for months to prepare

　　All this adds up-to a-tot of work-“hitting the books”． Knowledgeisaprizethatisnoteasytogain．

　　48．What does the underlined expression“hit the books“probably mean___？

　　A．Throw away books．

　　B．Study hard on a subject．

　　C．Hit desks with books．

　　D．Take tests with great care．

　　49．Most American students begin hitting the books for long hours___．

　　A．when they are in primary school

　　B．When they are in college

　　C．after they graduate from high school

　　D．when they reach high school

　　50．The students who___will take a test called SAT．

　　A