题目内容
（请给出正确答案）
Researchers have established the() between smoking and cancer.
A link
B chain
C join
D economy
简答题官方参考答案
（由简答题聘请的专业题库老师提供的解答）
更多“Researchers have established the（) between smoking and cancer.A linkB chainC joinD econo”相关的问题
Section B
Directions: There are 2 passages in this section. Each passage is followed by some questions or unfinished statements. For each of them there are four choices marked A, B, C and D. You should decide on the best choice.
Though explaining the entire human genetic blueprint is still a few years away, scientists have begun laying claim to the stretches of DNA whose codes they have succeeded in cracking. In recent years researchers have flooded the U.S. Patent and Trademark Office with applications for thousands of genes and gene fragments — and they have stirred a lot of controversy in the process.
The biggest problem with patenting genes is that while scientists have at least a general idea of what specific strands of genetic coding do, often it's just that — general. Investigators do sometimes succeed in isolating a single, crisp gene with a single known function. Often, however, researchers trying to map genes get no further than marking off fragmentary stretches of DNA that may be thousands of bases in length. These so-called expressed sequence tags may have real genetic information embedded in them, but determining where those fragments are and what their structure is takes more digging. Geneticists have lately been filing patent applications for these ESTs anyway. "I would guess that in many cases the scientists didn't even examine all the material," says Bruce Lehman, commissioner of the Patent and Trademark Office.
Not only can such filings be careless genetics, they can also be bad business. EST applications may lead to so-called submarine patents, claims that are made today and then vanish, only to reappear when some unsuspecting scientist finds something useful to do with genes hidden in the patent.
More troubling is an economic issue. If the entire genetic schematic is preemptively (抢先) owned by the research teams studying it now, where is the incentive for independent scientists — often sources of great innovation — to work on it later: Licensing costs, warns Jeffrey Kahn, director of the University of Minnesota's Center for Bioethics, could hold medical progress hostage. Patenting supporters insist that an equally persuasive argument could be made that the large genome-mapping groups need patent protection to make their work worthwhile to them.
Stickier than the economic question is the ethical one. Most of us shrink from the idea of anyone's owning the rights to any part of the human form. Besides, if the first anatomist (解剖学家) to spot, say, the pancreas (胰腺) was not granted title to it, why should modern genome mapping scientist be able to claim even a single gene: That kind of argument is grounded not in law but in the very idea of what it means to be human — an issue that even the highest federal court is not likely to settle.
Which of the following is true about the expressed sequence tags？
A．They are difficult to mark off.
B．They contain unidentified genetic information.
C．They contain the entire human genetic information.
D．They are genes whose specific functions have been identified.
the + ~ est /(most+形容词)+ 名词 + (that) + 主词 + have ever + seen (known/heard/had/read, etc)
The researchers have just completed a study of driving situations.
A．started
B．finished
C．changed
D．made
The researchers have tested their spray in the lungs.
A．Right
B．Wrong
C．Not mentioned
Researchers have discovered that dolphins are able to mimic human speech.
A．import
B．imitate
C．impair
D．humor
Brain researchers have discovered that the formation of new habits can be ______.
A．predicted
B．regulated
C．traced
D．guided
A．subjective
B．subordinate
C．liable
D．vulnerable
警告：系统检测到您的账号存在安全风险
为了保护您的账号安全，请在“简答题”公众号进行验证，点击“官网服务”-“账号验证”后输入验证码“”完成验证，验证成功后方可继续查看答案！
