请问这几句话是什么意思啊？

dhhgh11

全部来自　　白勇　GMAT语法全解

p90,14

Although the Supreme Court ruled as long ago as 1880 that Blacks could not be excluded outright from jury service, nearly a century of case-by-case adjudiction has been necessary to develop and enforce the principle that all juries must be drawn from “a fair cross section of the community”.

?P96 23

No less remarkable than the development of the compact disc has been the use of new technology to revitalize, in better sound than was ever before possible, some of the classic recorded performances of the pre-LP era.

P62, 17 The period when the great painted caves at Lascaux and Altamira were occupied by Upper Paleolithic people has been established by carbon-14 dating, but what is much more difficult to determine is the reason for their decoration, the use to which primitive people put the caves, and the meaning of the magnificently depicted animals

P64 20, Declining values for farm equipment and land, the collateral against which farmers borrow to get through the harvest season, are going to force many lenders tighten or deny credit this spring.

画线部分怎么译啊，谢谢！

teyvhf

p90,14

Although the Supreme Court ruled as long ago as 1880 that Blacks could not be excluded outright from jury service, nearly a century of case-by-case adjudiction has been necessary to develop and enforce the principle that all juries must be drawn from “a fair cross section of the community”. (一个平等交容的社区部门)

?P96 23

No less remarkable than the development of the compact disc has been the use of new technology to revitalize, in better sound than was ever before possible, some of the classic recorded performances of the pre-LP era.用新的科技去振兴那些传统的录音方式不比CD的发明差

P62, 17 The period when the great painted caves at Lascaux and Altamira were occupied by Upper Paleolithic people has been established by carbon-14 dating, but what is much more difficult to determine is the reason for their decoration, the use to which primitive people put the caves, and the meaning of the magnificently depicted animals．被Upper这帮人占据的位于L和A的画窟时期是通过炭－１４来测定的．但是更难测定的是这些装饰的理由，作用和意义．