题目

You either have it or you don’t — a sense of direction, that is. But why is it that some people could find their way across the Sahara without a map, while others can lose themselves in the next street? Scientists say we’re all born with a sense of direction, but it is not properly understood how it works. One theory is that people with a good sense of direction have simply worked harder at developing it. Research being carried out at Liverpool University supports this idea and suggests that if we don’t use it, we lose it. “Children as young as seven have the ability to find their己知NA为阿伏加德罗常数的数值，下列说法正确的是A. 25℃时，pH=13的1.0LBa(OH)2溶液中含有的OH-数目为0.2NAB. 一定条件下在密闭容器中2 molSO2与2 molO2充分反应，最终的气体分子数为3NAC. 将lmolNH4NO3溶于稀氨水中使溶液呈中性，溶液中NH4+数目为NAD. 4.6g乙醇含有共价键的数目为0.9NA