单选题Passage1Soon after starting his job as superintendent of the Memphis，Tenn.，public schools，Kriner Cash ordered an assessment of his new district's 104，000 students. The findings were depressing：nearly a third had been held back at least one academic yea

Passage1Soon after starting his job as superintendent of the Memphis，Tenn.，public schools，Kriner Cash ordered an assessment of his new district's 104，000 students. The findings were depressing：nearly a third had been held back at least one academic year. The high school graduation rate had fallen to 67%.One in five dropped out. But what most concerned him was that the number of students considered highly mobile，meaning they had moved at least once during the school year，had ballooned to 34，000，partly because of the home-foreclosure crisis. At least 1，500 students were homeless-probably more.I had a whole array of students who were angry，depressed，not getting the rest they needed，Cash says. It led him to consider an unusual proposition: What if the best way to help kids in impoverished urban neighborhoods is to get them out？Cash is now calling for Memphis to create a residential school for 300 to 400 kids whose parents are in financial distress，with a live-in faculty rivaling those of elite New England prep schools. If Cash's dream becomes a reality，it will probably look a lot like SEED，a charter school in Southeast Washington，which stands for Schools for Educational Evolution and Development. Its  320 students-seventh-to 12th-graders-should live on campus five days a week. They are expected to adhere to a strict dress code and keep their room tidy. There are computers in the dorm's common areas, and each student in grades 10 and above is given a desktop computer. At 11:30 every night it's lights out.In his plan for Memphis, Cash wants even more time. Perhaps the most provocative aspect of his proposal is to focus on students in grades 3 through 5 for homelessness is growing sharply among kids at that critical age, when much of their educational foundation is set, Cash says. His aim: to prevent illiteracy and clear other learning roadblocks early, so the problem won't migrate into middle and high school. Students will remain on campus year-round. The school would cost up to S50,000 a day to operate-three times the cost of a traditional day school with more than twice as many students.It sounds very exciting, but the devil is in the details. says Ellen Bassuk, president of the National Center on Family Homelessness in Newton, Mass.What is Kriner Cash worried about most after knowing the result of the assessment?