题目

小强在显微镜下观察到洋葱表皮细胞后，兴奋地向同桌描述，并把显微镜轻轻挪动给同组的其他同学观察，但别人却看不清物像。你认为最可能的原因是( ) A . 没有调节粗准焦螺旋 B . 射入光线角度发生了改变 C . 显微镜的物镜调换了 D . 光圈大小发生了改变 答案：B根据表格内容，选择最佳答案。Study BooksLearning How to Learn $24.99Children who read this book show great interest in study. The pictures will help them understand it easily and quickly.Basic Study Manual $38.50Read this book and learn:What the three barriers （障碍）to study are and what to do about them.What to do if you are fed up with a subject.Children read it to improve the ability to study.How to Use a Dictionary for Children $35.00Read this book and learn:How to find words in a dictionary.What the different marks in a dictionary mean.How to use a dictionary to pronounce words correctly.Buy this book and help children unlock their education. What's more, you'll just pay (支付)50% for it before July 1, 2014.（1）According to the ads, these three books are for ___________.A.menB.parentsC.childrenD.women（2）The pictures in the book Learning How to Learn can_________.A.make the book beautifulB.make the children draw beautifullyC.make the book sell wellD.make the children understand the book easily（3）_______ can tell you the meaning of the different marks in a dictionary.A.Learning How to LearnB.Study skills for LifeC.Basic Study ManualD.How to Use a Dictionary for Children（4）If you buy the three books on June 18,2014, you will have to pay ______ for them.A.$98.49B.$49.25C.$80.99D.$79.24（5）The purpose（目的）of the passage is to _______.A.sell the three books to childrenB.help children learn EnglishC.help children learn about natureD.use a dictionary to pronounce correctly