女，30岁，有月经过多史1年，Hb80g/L，WBC8．0×10⁹／L，PLT180×10⁹／L，网织红细胞0．015，血涂片可见红细胞中心淡染区扩大，对明确诊断没有意义的是（）

A.血清铁测定

B.总铁结合力测定

C.血清铁蛋白测定

D.骨髓铁染色检查

E.⁵¹铬红细胞半寿命期测定

Education is compulsory and free for every child in the United States. Most children start school by the age of six. They attend eight years of (36) schools and four years of high school or (37) school. The money for free public schools comes from taxes, and each state is (38) for its own educational system. State legislatures set the educational requirements but leave the (39) of the schools in the hands of the (40) communities. Most states require their children to go to school until a certain age. This age (41) from 10 to 18 years according to the laws of the (42) states. The Federal government (43) funds to the states for additional school and school services.
(44) . One may go to a twoyear college, a four year college, a university, or a specialized professional school—either public or private. Most colleges admit students on the basis of their high school records. (45) . Many students receive scholarships from the schools, governments, or private foundations and organizations. (46) . Only 2 percent of the population of the country cannot read and write.