题目

已知某种细菌以CO2为唯一碳源，下列相关叙述正确的是A. 可推测该细菌的代谢类型为自养需氧型B. 无机盐是该细菌不可缺少的营养物质C. 培养过程中碳源同时充当该细菌的能源物质D. 培养该细菌的培养基中无需添加氮源 答案：【答案】B【解析】某种细菌以CO2为唯一碳源，可推测该细菌的代谢类型为自养型，但不确定是否为需氧型，A项错误；无机盐参与复杂有机物的组成，是该细菌不可缺少的营养物质，B项正确；CO2不能作为能源，C项错误；氮元素参与核酸、蛋白质的组成，培养该细菌的培养基中需要添加氮源，D项错误，Happiness is for everyone. You don’t need to care about those people who have beautiful houses with large gardens and swimming pools or 1.and so on. Why? Because those who have big houses may often feel lonely and those who have cars may want to walk on the country roads at their free time.In fact, happiness is always around you if you put your heart into it. 2.. When you study hard at your lessons, your parents are always taking good care of your life and your health. When you get success, your friends will say congratulations to you. When you do something wrong, people around you will help you to correct it. 3.All these are your happiness. If you notice a bit of them, you can see that happiness is always around you.Happiness is not the same as money. It is a feeling of your heart. When you are poor, you can also say you are very happy, because you have something else that can’t be bought with money. 4., because you have more chances to challenge yourself with those difficulties. So you cannot always say you are poor and you have bad luck. As the saying goes, life is like a revolving(旋转的)door. When it closes, it also opens. 5..A. When you are in trouble at school, your friends will help youB. If you take every chance you get, you can be a happy and lucky personC. those who have nice cars and a lot of moneyD. And when you do something good to others, you will feel happy, tooE. those who have no housesF. If you meet with something frightening, you can give them up and be happy G. When you meet with difficulties, you can say loudly you are very happy