单细胞生物与人类有着密切关系．下列单细胞生物中，普通培养，繁殖速度快，可以作为研究生物科学的好材料的是{#blank#}1{#/blank#}；可以作为监测环境污染的指示动物的是{#blank#}2{#/blank#} ；可用于酿酒的是{#blank#}3{#/blank#}。

A眼虫    B草履虫    C酵母菌    D变形虫．

    The most important lessons in life that we need to learn are the results of our poor decisions. Although time and experience are the best teachers, we also suffer from experiences such as our sacrifices, suffering and the hardships. Good judgment develops only when we truly learn from our mistakes. However, many people keep repeating the same mistakes before learning their lessons because as they say, they are just humans who are subject to making mistakes.

Our weaknesses in life can be turned into our strengths if we immediately acknowledge and recognize the fact that we mess up and learn from them. Our good or bad experiences help us learn better judgment in life. Yet, too many people are in denial and place the blame on others without realizing that the minute they take responsibility for their action is when the learning process begins. Apart from learning from our own experience, we can also learn valuable lessons from the experience of others. It allows us to observe our behavior from another angle. When we recognize our mistakes and prevent them from happening again, we are, therefore, learning.

    Quickly identifying our mistakes and changing behavior accordingly requires less time and energy than denying mistakes. However, acknowledgement of mistakes requires belief in the idea that the perfection is not possible.

    It is easier to analyze our mistakes especially when we talk to others, which can help people to sort out comments or criticisms after a mistake is made. Despite our tendency to avoid mistakes, timely acknowledgement is one of the best ways to prevent them from repeating.

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已知a﹣b=1，则代数式2a﹣2b+2014值是{#blank#}1{#/blank#}