同位语从句
一、普通情况 1、形式 the this a/an 0 + 某些抽象名词 + that从句 no 形容词 物主代词 2、特点 “that”叫“连接词”，在从句中无词义、无语法成分 3、译法 (1)“～这一…”；“～的…”
The assumption(假设) that β= constant(恒定的) is often made to simplify(简化) analysis(分析). R= r is the condition(条件) that power(功率) delivered(提供) by a given(给定的) source(电源) is a maximum(最大值). Here we have used the definition(定义) that acceleration(加速度) is the rate(速率) of change of velocity. (2)“这一…：～”，“以下的…：～” This accounts for(解释) the observation(观察到的情况) that the resistivity(电阻率) of a metal(金属) increases with temperature.
The latter(后一) form(形式) has the advantage(优点) that it can be extended(扩展) to complex(复杂的) quantities(量). (3)“动宾译法”（这时该“抽象名词”来自于可带有宾语从句的及物动词） During the past several years, there has been an increasing(增长的) realization(认识) within business(商业) and academic(学术的) circles(界) that certain(某些) nations(国家) have evolved(发展) into information(信息) societies(社会).
The main(主要的) theoretical(理论的) development(进展) in this decade(十年) has been in the recognition(认识) that material(材料) properties(性质) should be included(包括) in the analytical(分析的) models(模型). This is equivalent to(等效于) a statement(陈述) that everything is attracted(吸引) by the earth(地球).
A consequence(结果) of the discovery(发现) of electricity(电) was the observation(观察) that metals(金属) are good conductors(导体) while non-metals(非金属) are poor(不良的) conductors. 4、几个句型 (1)“there is evidence that …”→“有证据表明…” There is evidence(证据) that Ohm’s law(定律) applies(适用) only to metallic(金属的) conductors.
(2)“there is no doubt that …”→“毫无疑问…” There is no doubt(疑问) that mercury(水银) is a metal. (3)“there is every possibility that …”→“完全有可能…” There is every possibility(可能性) that satisfactory(理想的) results(结果) will be obtained(获得).