题目

下列情况中，使用普通光学显微镜不能观察到的是 A．人红细胞在蒸馏水中体积增大、破裂的现象 B．洋葱鳞片叶表皮细胞膜的暗 - 亮 - 暗三层结构 C．分布在水绵受极细光束照射部位的好氧细菌 D．洋葱根尖细胞有丝分裂中期染色体的形态和分布 答案：B【解析】 洋葱鳞片叶表皮细胞膜的暗 -亮 - 暗三层结构属于亚显微结构，在电子显微镜下才能看到。其余属于光镜下可以看到的显微结构。 【考点定位】显微镜 【名师点睛】解答此题的关键是题干中要求的 “使用普通光学显微镜不能观察到的 ” ，普通光学显微镜只能呈现显微结构，而对于更加精阅读理解 　　The latest Harry Potter book may have a side effect. 　　A Washington doctor said that he had treated three children with headaches caused by reading through the 870-page adventure. 　　The doctor called them Hogwarts Headaches, named after the wizard school that Harry attends. 　　The doctor wrote that the three children, aged 8 to 10, experienced a headache for two or three days. Each had spent many hours reading Harry Potter and the Order of the Phoenix. 　　The doctor told his patients to give their eyes a rest. But the spell (咒语) cast by Harry Potter was clearly too powerful.“The obvious cure－that is, taking a break from reading－was rejected by two of the patients,”he said. 　　In each case, the headache went away only after the patient turned the final page. 　　Harry Potter and the Order of the Phoenix, the fifth book in the series, has nearly three times as many pages as Harry Potter and the Sorcerer’s Stone, the first book, and J. K. Rowling still plans two more books. 　　“If this escalation (页数增加)continues as Rowling concludes the story, there may be an epidemic (流行病)of Hogwarts Headaches in- the years to come,”the doctor predicted(预言). He warned that reading continuously for a long time was very harmful to the eyes. 1．The underlined word“rejected”probably means”________”. [　　] A．refusedB．agreed C．satisfiedD．taken 2．What can we know from this passage? [　　] A．Harry Potter books are written only for children. B．Harry Potter books are really attractive to children. C．Harry Potter books can cause headache. D．The three children like the treatment in the hospital. 3．What caused the three children’s headache? [　　] A．Spending too much time reading Harry Potter books. B．The spell cast by Harry Potter. C．Some kind of epidemic. D．The final page of Harry Potter books. 4．Which of the following is TRUE according to the passage? [　　] A．The first book of J. K. Rowling is three times as thick as her fifth one. B．J. K Rowling hopes to write at least seven books. C．The epidemic of Hogwarts Headaches will spread in the near future. D．Reading for a long time non-stop does good to one’s head. 5．What is the best title for the passage? [　　] A．How to cure Hogwarts Headaches B．The 870-page adventure C．Harry Potter causes headaches D．Harry Potter and J.K.Rowling