问题 单项选择题

生物柴油一直被誉为是减少我们对化石燃料依赖的可能的解决办法。目前大部分采用生物柴油的车辆使用的都是经过再加工的食用油,这种生物柴油的原材料非常昂贵,而且也很稀缺,因此很难进行大规模商业生产。如果生物柴油想对现实生活产生不可磨灭的真正影响,它就必须直接来源于植物。斯坦福大学的研究人员表示,生产价格低廉的植物生物柴油的化学过程很快就会变成现实。
最近通过大肠杆菌进行的试验表明,这种细菌可能是把植物成功转变成生物柴油的关键。利用植物切实可行地生产生物柴油是一个非常复杂的过程,迄今为止还没有用植物大规模生产这种燃料的可行方法。大肠杆菌能把植物糖分转变成脂肪酸衍生物,一种与肥皂类似的化学物质,是一种行得通的燃料的好前体。但是科学家还不确定这种细菌是否具有可供大规模生产的足够的化学“能力”。斯坦福大学的研究人员进行了相关研究,他们想看一看大肠杆菌在把糖转变成脂肪酸衍生物方面是否存在理论上的“限制”,例如这种细菌是否有能力将常规植物转变为“燃料”。相关研究报告称,这个问题的答案显然是肯定的。研究人员表示:“好消息是大肠杆菌制造脂肪酸衍生物具有令人难以置信的超强能力,它能以极高的速度把糖转变成燃料。”
但是这一过程受到细菌的严密控制,因此我们需要更好地了解大肠杆菌。科研小组已经开始进行这方面的工作,并在实验室环境下隔离了产生脂肪酸衍生物的分子机制。他们说:“我们想弄明白是什么限制了大肠杆菌处理糖的能力。我们正在询问的这个问题就像是什么限制汽车车的速度达到每小时150英里的问题。”
我们发现,大肠杆菌限制脂肪酸衍生物产生的目的,显然是为了阻止这种物质对它造成伤害。它采取的“防御措施”非常有效,但是研究人员已经开始研究如何能让这种细菌产生更多脂肪酸衍生物。如果研究取得成功,生物柴油将会突然从一个传奇转变成切实可行的商用燃料。

根据本文,下列说法正确的是______。

A.由植物糖分转变成的脂肪酸衍生物就是生物柴油
B.大肠杆菌生存环境对脂肪酸衍生物分子生成机制有影响
C.细菌分解糖分过程中一定会产生脂肪酸衍生物
D.目前生物柴油的商用生产尚处于研究阶段

答案

参考答案:B

解析: 由“大肠杆菌能把植物糖分转变成脂肪酸衍生物,一种与肥皂类似的化学物质,是一种行得通的燃料的好前体”可知,脂肪酸衍生物并不是生物柴油,A项错误。C项“一定会产生”表述绝对,与文意不符,排除。D项“尚处于研究阶段”与第一段的“目前大部分采用生物柴油的车辆使用的都是经过再加工的食用油”不符,排除。B项可由倒数第二段得出。本题答案为B。

填空题
完形填空
How to Argue with Your Boss
Before you argue with your boss, check with the boss’s secretary to determine his mood. If he ate nails for breakfast, it is not a good idea to ask him for something. Even without the boss’s secretary, there are keys to timing: don’t approach the boss when he’s on deadline; don’t go in right before lunch, when he is apt to be distracted and rushed; don’t go in just before or after he has taken a vacation.
If you’re mad, that will only make your boss mad. Calm down first. And don’t let a particular concern open the floodgates for all your accumulated frustration. The boss will feel that you think negatively about the company and it is hopeless trying to change your mind. Then, maybe he will dismiss you.
Terrible disputes can result when neither the employer nor the employee knows what is the problem the other wants to discuss. Sometimes the fight will go away when the issues are made clear. The employee has to get his point across clearly in order to make the boss understand it.
Your boss has enough on his mind without your adding more. If you can’t put forward an immediate solution, at least suggest how to approach the problem. People who frequently present problems without solutions to their boss may soon find they can’t get past the secretary.
To deal effectively with a boss, it’s important to consider his goals and pressures. If you can put yourself in the position of being a partner to the boss, then he will be naturally more inclined to work with you to achieve your goals.
小题1:Paragraph 2 ______
小题2:Paragraph 3 ______
小题3:Paragraph 4 ______
小题4:Paragraph 5 ______
A. Keep Your Voice Low All the Time
B. Put Yourself in the Boss’s Position
C. Propose Your Solution
D. Don’t Go in When You Are Angry
E. Make the Issue Clear
F. Never Give in
 
小题5:If you want to ask the boss for anything, it is important to find out first _________.
小题6:It is necessary to make clear to the boss ___________.
小题7:It is not wise to present the boss with a problem ___________.
小题8:You must be considerate and think of the troubles ____________.
A. to give the boss your advice
B. how he is feeling
C. the boss may have
D. what you really want to talk to him about
E. without suggesting a way to solve it
F. how unhappy you are