完成时和现在时应该怎么选择？

miejue

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 adjudication has been necessary to develop and enforce the principle that all juries must be drawn from “a fair cross section of the community.”
(A) has been necessary to develop and enforce the principle that all juries must be
(B) was necessary for developing and enforcing the principle of all juries being
(C) was to be necessary in developing and enforcing the principle of all juries to be
(D) is necessary to develop and enforce the principle that all juries must be
(E) will be necessary for developing and enforcing the principle of all juries being

这里A和D只是完成时和现在时的区别 答案是A 我同意 可是不知道和现在时有什么区别吗？

chwayne

Dear Miejue,

XDF认为在以下三种情况下得用现在完成时:

1) 有since   
2) 大段的时间概念,如: century decade 等等
3) 有如: the world has never seen 或者是never before 等等

不知是否完整, 请参考

gemj

从逻辑上nearly a century of case-by-case adjudication
有必要好象与现在完成时搭配好一些。
过去的有必要，现在的仍然有必要。
如果是现在时“一百年来的个案裁决（现在）是必要的”
虽然不能算错，但好象不太好。