In 1995 Richard Stallman, a well-known critic of the patent system, testified in Patent Office hearings that, to test the system, a colleague of his had managed to win a patent for one of Kirchhoff's laws, an observation about electric current first made in 1845 and now included in virtually every textbook of elementary physics.
[size=1em]40. In 1995 Richard Staliman, a well-known critic of the patent system, testified in Patent Office hearings that, to test the system, a colleague of his had managed to win a patent for one of Kirchhoff's laws, an observation about electric current first made in 1845 and now included in virtually every textbook of elementary physics.
(A) laws, an observation about electric current first made in 1845 and
(B) laws, which was an observation about electric current first made in 1845 and it is
(C) laws, namely, it was an observation about electric current first made in 1845 and
(D) laws, an observation about electric current first made in 1845, it is
(E) laws that was an observation about electric current, first made in 1845, and is
In 1995 Richard Staliman(主语), a well-known critic of the patent system, (主语同位语)testified(谓语) in Patent Office hearings(状语) that(谓语的搭配testify that……), to test the system(不定式从句中作状语), a colleague of his(that宾语从句的主语)had managed(that 从句谓语) to win a patent for one of Kirchhoff's laws(that从句宾语至此从句主谓宾也全部出现), (此逗号后名词性补充说明成分)an observation about electric current (介词短语后置定语) first made in 1845(分词后置定语) and now included(分词定语2) in virtually every textbook of elementary physics.