题目

      When I was small and my grandmother died, I couldn't understand why I had no tears. But that night when my dad tried to cheer me up, my laughs turned into crying.       So it came as no surprise to learn that researchers believe crying and laughing are controlled by the same part of the brain. Just as laughing has many health advantages, scientists are discovering that so does crying.       Whatever helps us to reduce pressure is important to our emotional health, and crying seems to work well. One study found that 85 percent of women and 73 percent of men report 11．通过下列实验操作和现象能得出相应结论的是（　　）  实验操作现象结论A向收集满CO2的软塑料瓶中加入约1/3体积的紫色石蕊溶液，旋紧瓶盖，振荡塑料瓶变瘪且紫色石蕊变红CO2能与石蕊反应B50℃时，将17gKCl固体加入50g蒸馏水中，完全溶解后缓慢降温降温至20℃时开始有晶体析出20℃时，KCl的溶解度为17gC将白磷浸没在热水中，再向热水中的白磷通氧气通氧气前白磷不燃烧，通氧气后白磷燃烧氧气是燃烧需要的条件之一D点燃从导管放出的某气体，在火焰上方罩一个冷而干燥的烧杯烧杯内壁有无色液滴产生该气体是CH4A．AB．BC．CD．D