Carl Sagan believes that Venus might be colonized from earth because ________.

A．you should only do things for which you have the ability B．only important jobs are worth doing well C．you should only attempt worthwhile jobs D．anything you do should be done to your best ability

A．drinking coffee was unpatriotic B．2000 insurance companies were set up hundreds of years ago C．Europeans were responsible for the existence of slavery D．coffee actually influenced the rise of business

A．mutated genes have a negative influence on Ashkenazim"s intelligence B．mutated genes have played a role in Ashkenazim"s intelligence C．the Ashkenazim"s high intelligence is caused by the mutated genes D．the Ashkenazim"s illnesses have greatly handicapped their performance 此题为多项选择题。

A．may improve handling of livestock B．may help control the spread of Mad Cow Disease C．may hurt the economy by eliminating small farmers D．may make food even less safe

A.many teachers are opposedto the idea of being evaluated by the students B.students are opposed tothe idea of evaluating the teachers on their own C.students fear that theyare likely to be criticized by their teachers if they are to give theirassessments D.many teachers fear that theyare likely to criticize the students who have given their assessments

A．be learned at an early age B．not be confused with body language C．not be confused with written language D．be learned in the context of a caring relationship

A．dressing appropriately of women politicians would not be worthy of comment any more B．we have the definition of what Sen. Clinton wears, and that should be end of her style. analysis C．no distraction would be earned for those politicians in uniform D．women politicians would like to make changes and invite analysis. 此题为多项选择题。

A．doing well on some examinations B．being an excellent student at school C．knowing quickly how to solve a problem D．a certain positive type of behavior. or attitude

A．won the race by his own effort B．took a risk by agreeing to race C．was not given a fair chance in the race D．won the race by chance

A.women have to show theirbeauty through their looks B.beautiful clothes can makewomen more attractive C.women should lay moreemphasis on their owrl qualities D.women are more curiousabout new things than men

A.has seldom been accompanied by climatic changes B.has exerted little influence on climatic changes C.has largely been effected by climatic changes D.has had a major impact on climatic changes

A.acceptable despite the criticism. B.harmful to the culture of research. C.subject to undesirable changes. D.unworthy of public attention.

A．is a victim of the male dominance B．lacks initiative C．hates royal figures D．is selfish

Many researchers believe that the presence of RNA in brain cells is the biochemical basis of memory; that is, the presence of RNA enables us to remember. Because certain chemicals are known to inhibit the synthesis of RNA in the body, we can test this hypothesis. Animals that have learned particular responses can be injected with an RNA inhibitor and then tested for memory of the learned responses. Which of the following test results would most seriously weaken the case for RNA as the basis of memory？ A．After an injection of RNA inhibitor, a wide range of behaviors in addition to the learned responses were affected. B．After an injection of RNA inhibitor, animals that had not consistently been giving the learned responses were able to give them consistently. C．After injections of RNA inhibitor, some animals lost memory of the learned responses totally but others lost it only partially. D．After a small injection of RNA inhibitor, animals responded well, but as the size of the injection increased, they gave fewer of the learned responses. E．After an injection of RNA inhibitor, animals could not learn a new response.

A．learning is important for its own sake B．it"s understandable to pay kids for test scores C．paying kids to learn is what schools strive for D．pay-to-learn is against our notion about education

A．everyone gets a chance to be successful by their own efforts and talents B．everyone has the right of all individuals to control their own destiny C．everyone is the members of a close-knit, interdependent collectivity D．everyone is responsible for their own situations in life 此题为多项选择题。

A．necessary B．common C．bad for heath D．good for health

A．the rich could become kindhearted people to help the poor B．all social evils could not be remedied C．human society would become worse D．virtue and evil exist at the same time in humanity