【单选题】下列哪项不是肉毒梭菌的特
A.
肉毒毒素作用于胆碱能神经末梢,抑制乙酰胆碱的释放
【简答题】碳酸钙可用于预防和治疗钙缺乏症。某实验小组同学要测定一种钙片中碳酸钙的含量。 【查阅资料】获得的资料有:①补钙剂中常加入糖类、维生素D等改善口感或增强药效。这些物质不与稀盐酸反应产生气体,高温灼烧时会燃烧或分解。 ②碳酸钙高温灼烧分解生成氧化钙和二氧化碳。 ③常见的碳酸钙含量测定方法:将碳酸钙粉碎,加入已知浓度的过量盐酸充分反应,然后测剩余盐酸的量,根据消耗盐酸的量最终求得碳酸钙的含量。 ④澄清石...
【判断题】It usually takes into account the meanings and functions sentences have in the overall system of the language.()
【简答题】The sale usually takes place outside the house, ?The sale usually takes place outside the house, with the audience _____ on benches , chairs or boxes. A) having seated B) seating C) seated D ) having ...