搜题请搜索小程序“爱下问搜题”
问题 填空题

我市某县有较丰富的煤炭和石灰岩资源，当地利用这些资源进行炼焦、炼铁．写出在炼铁过程中涉及到的以下两个反应的化学方程式．

（1）石灰石（主要成分为CaCO3）高温分解______；

（2）赤铁矿（主要成分为Fe2O3）在高温下与一氧化碳反应______．

答案

（1）石灰石高温分解，反应物位碳酸钙，反应条件为高温，生成物为氧化钙和二氧化碳，故其反应的化学方程式为：CaCO3

 高温 
.
 
CaO+CO2↑；

（2）一氧化碳和赤铁矿（主要成分是Fe2O3）在高温下反应冶炼成铁的反应物位三氧化二铁和一氧化碳，反应条件为高温，生成物位铁和二氧化碳，

其化学反应式是：Fe2O3+3CO

 高温 
.
 
2Fe+3CO2；

故答案为：（1）CaCO3

 高温 
.
 
CaO+CO2↑；（2）Fe2O3+3CO
 高温 
.
 
2Fe+3CO2；

完形填空

阅读短文，根据短文内容及首字母提示，在空白处填入一个适当的单词。

Do you like animals? Do you want to keep animals? Yes, many people like animals and want to keep a lovely animal as a （71） p_____. It's a pity that they don't have a suitable place to keep them. However, keeping fish may be the best choice.

Why keep them?

People keep dogs and cats because they enjoy their friendship. Fish can not be friendly, but they have beautiful shapes and colors. It's a pleasure to watch as they swim （72）i_____ their tank（水槽）.

What do they need?

First of all, the fish need a suitable （合适的） tank, and you must fill the tank （73） w_____ suitable water. It is also good for （74） t_____ to have a few water plants in the tank to keep the water pure （纯净）. Putting a few snails （蜗牛） in the tank is a good （75） i_____. They will keep it （76） c_____

What about feeding them?

There are many kinds of fish food （77） t_____ you can get in the shops. Most are suitable for all kinds of fish. You should feed your fish only （78） o_____ a day. It is important not to give them （79） t_____ much food. Just give them as much as they can （80） e_____ up in about 15 minutes. This will keep them healthy.
查看答案
多项选择题

导致企业财务决策失误的主要因素包括（）

A.第一种危险无疑来自错误的投资决策

B.第二种危险来自企业成长中的财务失控

C.第三种危险来自企业中的个人主义

D.第四种危险来自过度投资思想指导下形成的融资组合风险

E.以上都对
查看答案