题目

Hong Kong is the world's shark fin capital.But a backlash(强烈抵制) from environmentalists and consumer groups is pressuring restaurants to stop serving dishes containing the shark fin. Around 50 percent of all shark fins worldwide are traded through Hong Kong.In 2008，around 10，000 tons of fins from 87 countries passed through the city's ports.For environmentalists like Stanley Shea of French­founded Bloom Association，that must change.He is trying to raise awareness in Hong Kong.Shea and his fellow activists have been quite effective.Over the last two years governments in Ho用NA表示阿伏加德罗常数的值。下列叙述中一定正确的是（　 　）A.一定条件下4.6 g Na完全与O2反应生成7.2 g产物,失去的电子数为0.2NAB.50 mL 18.4 mol/L浓硫酸与足量铜加热反应,生成SO2的分子数为0.46NAC.一定条件下某密闭容器盛有0.1 mol N2和0.3 mol H2,充分反应后转移电子数为0.6NAD.电解1 L NaCl溶液至c（OH-）=0.2 mol/L,转移电子数为0.4NA