托福语法课程讲义:语法三大从句-名词性从句

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　　第三课

　　3.1. 三大从句-名词性从句

　　3.2. 名词性从句-主、宾、表、同

　　3.3. 阅读实战举例

　　问题一：什么是名词性从句?

　　要搞清这个问题，首先要搞清：

　　名词或名词短语可以做什么句子成分

　　答案：主、宾、表、同

　　如果把句子当作名词来用，分别去充当另一句话的主、宾、表、同。便构成了主语从句、宾语从句、表语从句和同位语从句。即名词性从句。

　　名词性从句--主语从句演绎

　　名词性从句—宾语从句演绎

　　名词性从句—表语从句演绎

　　名词性从句—同位语从句演绎

　　问题二：老师我已经知道了，原来一个句子去充当另一个句子的四种成分时就构成了名词性从句。但是问题是哪些句子可以去充当这四种成分呢?

　　答案：三种句子充当四种成分。

　　1. 陈述句;2. 一般疑问句;3. 特殊疑问

　　一、陈述句作句子成分

　　要在陈述句句首加上that

　　“that+陈述句”这一结构分别充当另一个句子的主语、宾语、表语或者同位语等四种成分。

　　二、一般疑问句作句子成分

　　1)用whether或if引导

　　2)if 还是whether?

　　if一般只用于引导宾语从句，而whether可引导包括宾语从句在内的其他名词从句。

　　三、特殊疑问句作句子成分

　　1)变倒装语序为陈述语序。

　　2)特殊疑问词作主语，无需调整句子语序

　　Who will chair the meeting has not yet been

　　decided.

　　名词性从句的引导词总结

　　Great comic art is never otherworldly, it does not seek to mystify us, and it does not deny ambiguity by branding as evil whatever differs from good. Great comic artists assume that truth may bear all lights, and thus they seek to accentuate contradictions in social action, not gloss over or transcend them by appeals to extra-social symbols of divine ends, cosmic purpose, or laws of nature. The moment of transcendence in great comic art is a social moment, born out of the conviction that we are human, even though we try to be gods. The comic community to which artists address themselves is a community of reasoning, loving, joyful, compassionate beings, who are willing to assume the human risks of acting rationally. Without invoking gods or demons, great comic art arouses courage in reason, courage which grows out of trust in what human beings can do as humans.

　　The evolution of sex ratios has produced, in most plants and animals with separate sexes, approximately equal numbers of males and females. Why should this be so? Two main kinds of answers have been offered. One is couched in terms of advantage to population. It is argued that the

　　5 sex ratio will evolve so as to maximize the number of meetings between individuals of the opposite sex. This is essentially a group selection argument. The other, and in my view correct, type of answer was first put forward by Fisher in 1930. This "genetic" argument starts from the assumption that genes can influence

　　That sex ratio will be favored which maximizes the number of descendants an individual will have and hence the number of gene copies transmitted. Suppose that the population consisted mostly of females: then an individual who produced sons only would have more grand children. In

　　15 contrast, if the population consisted mostly of males, it would pay to have daughters. If, however, the population consisted of equal numbers of males and females, sons and daughters would be equally valuable. Thus a one-to-one sex ratio is the only stable ratio; it is an evolutionarily stable strategy. Although Fisher wrote before the mathematical theory of games

　　20 had been developed, his theory incorporates the essential feature of a game—that the best strategy to adopt depends on what others are doing.

　　Since Fisher's time, it has been realized that genes can sometimes influence the chromosome or gamete in which they find themselves so that the gamete will be more likely to participate in fertilization. If such a

　　25 gene occurs on a sex-determining (X or Y) chromosome, then highly aberrant sex ratios can occur. But more immediately relevant to game theory are the sex ratios in certain parasitic wasp species that have a large excess of females. In these species, fertilized eggs develop into females and unfertilized eggs into males. A female stores sperm and can

　　30 determine the sex of each egg she lays by fertilizing it or leaving it unfertilized. By Fisher's argument, it should still pay a female to produce equal numbers of sons and daughters. Hamilton, noting that the eggs develop within their host-the larva of another insect-and that the newly emerged adult wasps mate immediately and disperse, offered a

　　35 remarkably cogent analysis. Since only one female usually lays eggs in a

　　3given larva, it would pay her to produce one male only, because this one male could fertilize all his sisters on emergence. Like Fisher, Hamilton looked for an evolutionarily stable strategy, but he went a step further in recognizing that he was looking for a strategy.

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