听写填空,只写填空内容,不抄全文,5-10句,不用写标号,注意标点,口语中因结巴等问题造成的重复单词只写一遍~
Steven Benner: [---1-2---]
You are listening to Molecular biologist Steven Benner, he is talking about a molecule-sized step towards creating artificial life forms. [---3-5---]
Steven Benner: [---6-7---]
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Steven Benner: It’s an old question, right? How life originated is very closely tied to the question, are we alone? [---10---]
We’re at
【视听版科学小组荣誉出品】
In science you get excited by incremental steps, by even small things. And in a sense, this is an incremental step. The DNA of all life on Earth is made up of the same four chemical letters of the genetic code . Benner has designed a DNA molecule with eight new chemical letters in addition to the four natural letters. He said the next step is to make his artificial DNA self-sustaining. If you can retain artificial genetic alphabets in the copying process that means you have the ability to take the next step, which is make that copying self-sustaining. And that’s one of many steps that’s going to be taken as we try to get an artificial life form. Benner said artificial DNA molecules are used as medical tools, for example to help doctors monitor the level of HIV in a patient’s blood. But he said the creation and search for new forms of life goes much deeper. If there’s a lot of aliens out there, that means it must be easy to get life originating, and it must be easy to sustain life.