胰岛细胞中与胰岛素形成和分泌有关的结构是 A. 线粒体、中心体、高尔基体、内质网、细胞膜 B.核糖体、内质网、叶绿体、高尔基体、细胞膜 C. 内质
政治稳定、经济繁荣的北宋长期与辽、夏并立，其原因是（ ）A. 国际虚弱 B. 豪强争权 C. 藩镇割据 D. 分封诸侯
铝镁合金已成为飞机制造、化工生产等行业的重要材料。研究性学习小组的同学，为测定某含镁3％-5％的铝镁合金（不含其它元素）中镁的质量分数，
1985年科学家发现一种新物质，化学式为C60，下列说法中正确的是( ) A.该物质是混合物 B.该物质为新型化合物 C.该物质的相
Most dog owners believe their dogs experience guilt,but animal behaviorists say the “guilty look” of a dog is simply a reaction to you and that dogs lack the ability to feel shame. Alexandra Hor
He demanded that the laboratory report ___ immediately after the experiment was done. A. was written B. be written C. must be written D. would be writt
