问题 选择题

二氧化碳和氢气可在一定条件下反应,生成一种重要的化工原料甲醇:

CO2+3H2CH3OH+H2O。有关该反应的说法正确的是

A.钌-膦络合物的质量在反应前后发生了变化

B.氢原子数在反应前后发生了改变

C.属于复分解反应

D.体现了CO2的化学性质

答案

答案:D

题目分析:A选项因为是催化剂,故钌-膦络合物的质量在反应前后不变;B选项根据质量守恒定律可知,氢原子数在反应前后不变;C选项该反应不属于化合反应,因为氢气属于单质;D选项体现了二氧化碳的化学性质是正确的叙述.

单项选择题
单项选择题

People are indulging in an illusion whenever they find themselves explaining at a cocktail(鸡尾酒 ) party, say, that they are "in computers," or " in telecommunications," or "in electronic funds transfer". The implication is that they are part of the high-tech world. Just between us, they usually aren’t. The researchers who made fundamental breakthroughs in those areas are in a high-tech business. The rest of us are (11) of their work. We use computers and other new technology components to develop our products or to organize our affairs. Because we go about this work in teams and projects and other tightly knit working group(紧密联系在一起的工作小组 ), we are mostly in the human communication business. Our successes stem from good human interactions by all participants in the effort, and our failures stem from poor human interactions.
The main reason we tend to focus on the (12) rather than the human side of work is not because it’s more (13) , but because it’s easier to do. Getting the new disk drive installed is positively trivial compared to figurine out why Horace is in a blue funk(恐惧)or why Susan is dissatisfied with the company aver only a few months. Human interactions are complicated and never very crisp(干脆的,干净利落的) and clean in their effects, but they matter more than any other aspect of the work.
If you find yourself concentrating on the (14) rather than the (15) , you’re like the vaudeville character(杂耍人物)who loses his Keys on a dark street and looks for them on the adjacent street because, as he explains, "The light is better there!\

A.technical

B.classical

C.social

D.societal