题目

将 23g纯净物 M 在足量氧气中完全燃烧，生成 44g 二氧化碳和 27g 水。下列说法中不正确的是 A．消耗氧气 48g B． M 中含碳元素的质量分数约为 52.2% C． M 只含碳、氢元素 D． M 中碳元素和氢元素的质量比为 4:1 答案：C【解析】 【详解】 A、由质量守恒定律，参加反应的反应物的总质量等于生成的生成物的总质量，则消耗氧气的质量为 ，故 A正确； B、纯净物 M 在足量氧气中完全燃烧，氧气中不含碳元素，则二氧化碳中碳元素来自 M ， M 中含碳元素的质量为 ， M中含碳元素的质量分数约为 ，故 B正确； C、二 阅读理解 　　The following form shows the result of a survey(调查)of parents from five countries, who were asked why children are important to them．They were required to choose three main reasons from seven dealing with personal interests, family relations and social responsibility(责任)．Each number in the form is the percentage(％)of parents who chose that particular item(项)as one of their three reasons．Therefore, the most common for Japanese parents are strengthening family ties(Item D, 51％), learning from the experience(Item E, 60％), and raising responsible citizens(Item, G 45％)． (1) According to this survey, Korean parents are most interested in ________． [　　] A． continuing their family B． obtaining care in old age C． strengthening family relationship D． caring for raising children (2) How many items are chosen by parents of more than two countries as main reasons? [　　] A． Two． B． Three． C． Four． D． Five． (3) From the percentages in items ________, we can see the following difference between the Asian and the European countries：the Asian parents want to devote themselves to future societies through children; the European parents enjoy the course of raising children． [　　] A． B and C B． D and F C． E and F D． F and G (4) According to the form, which of the following is true? [　　] A． From the main reasons shown in the form it seems that in every country parents do not expect care from children in their old age． B． Japanese parents share two of their main reasons with the British and American parents, and the third one with Korean parents． C． More than half of the parents from each country chose the reason“tostrengthen family ties”and for each it was one of the three main reasons for having children． D． The percentage of French parents selecting the reason“to see oneself continuing in future”is about as high as that of the other countries．