题目

Many countries follow special customs when a child’s baby teeth fall out. Many of these customs tell stories about animals taking the teeth. For example, Koreans have the custom of throwing the fallen tooth onto the roof of a house so that a magpie (喜鹊) can take the tooth away and bring a new tooth for the child. This custom is also followed by some other Asian countries, such as Japan and Vietnam. Other countries, though, have tooth customs about other animals. In Mexico and Spain, for example, it is thought that a mouse takes a fallen tooth away and leaves some money. But in Mon用大豆新鲜绿叶进行如图所示的实验，置于充足的光照下，分析D处的气体成分，最可能的是（    ） A．氧气的量多于B处      B．氧气的量与B处相等 C．没有CO2和O2          D．CO2的量多于B处