题目

The schoolboy regretted ________ after he didn't pass his exam. A . the time on TV B . to spend too much time on TV C . taking most of his time on TV D . spending too much time on TV 答案：D 人们喜欢吃火锅，常用的火锅燃料是一种俗称“固体酒精”的物质。已知“固体酒精”是用酒精（C2H5OH）、醋酸钙和水按一定比例制成的“胶冻”。 （1）C2H5OH中C、H、O原子个数比为____________。 （2）若“固体酒精”充分燃烧时，只发生反应：C2H5OH + 3O2       2CO2 + 3H2O。现取“固体酒精”30 g，充分燃烧后生成44 g CO2。请计算“固体酒精”中C2H5OH的质量分数是多少？（结果保留一位小数）