题目

      Does happiness have a scent?  When someone is happy, can you smell it?  You can usually tell when someone is happy based on seeing them smile, hearing them laugh or perhaps from receiving a big hug. But can you also smell their happiness?       Surprising new research suggests that happiness does indeed have a scent, and that the    experience of happiness can be spread through smell, reports Phys.org.        For the study, 12 young men were shown videos meant to bring about a variety of emotions while researchers gathered sweat samples from them. All of the 33. 下图是菜豆和玉米种子的结构图。据图分析下列问题。 (1) 写出图中字母代表的名称。B ，C ，D ,E ，F ，G 。(2) 菜豆和玉米种子结构上的相同点是都有 和胚，而且胚都是由 、、 、组成，不同点是菜豆种子的子叶有 片，而玉米种子的子叶有 片，而且玉米中有 。(3) 玉米种子的 和紧贴在一起，不易分开，所以玉米粒应是 。(4) 向菜豆种子和玉米种子剖面滴稀碘液，变蓝色的结构分别是 、。