求教一个关于现在完成时的问题

1r1r1r

先前看OG12里一道关于现完的题：10、 Carnivorous mammals can endure what would
otherwise be lethal levels of body heat because they
have a heat-exchange network which kept the brain
from getting too hot.

which kept

that keeps

which has kept

that has been keeping

having kept

A    Kept is the wrong tense.
B    Correct. The verb keeps indicates a current
situation and is consistent with the other
verbs in the sentence. The sentence is clear
and concise.
C    Mistaken shift in tense: In this sentence the
present tense expresses a timeless general
principle; in contrast, has kept indicates a
more definite context and time period and
suggests that the heat-exchange network
may no longer have this effect.
D    Has been keeping is the wrong tense.
我对C解释的理解是现完表示以前发生的动作一直持续到现在，但是不延续到将来
再来看PREP语法笔记中的一道题
192. (GWD-7-Q20)The first trenches that were cut into a 500-acre site at Tell Hamoukar, Syria, have yielded strong evidence for centrally administered complex societies in northern regions of the Middle East that were arising simultaneously with but independently of the more celebrated city-states of southern Mesopotamia, in what is now southern Iraq.

A. that were cut into a 500-acre site at Tell Hamoukar, Syria, have yielded strong evidence for centrally administered complex societies in northern regions of the Middle East that were arising simultaneously with but
B. that were cut into a 500-acre site at Tell Hamoukar, Syria, yields strong evidence that centrally administered complex societies in northern regions of the Middle East were arising simultaneously with but also
C. having been cut into a 500-acre site at Tell Hamoukar, Syria, have yielded strong evidence that centrally administered complex societies in northern regions of the Middle East were arising simultaneously but
D. cut into a 500-acre site at Tell Hamoukar, Syria, yields strong evidence of centrally administered complex societies in northern regions of the Middle East arising simultaneously but also    (E)
E. cut into a 500-acre site at Tell Hamoukar, Syria, have yielded strong evidence that centrally administered complex societies in northern regions of the Middle East arose simultaneously with but



考点：逻辑表达，平行对称，简洁有效


4. 现在完成时时与一般现在时：
     yield用现在完成时与一般现在时都说得通，但是含义不一样，用have yield说明了the first trenches是过去发现的，至今仍能提供证据，而yield的话则是说明是现在发现的，所以用have yield更合理


(E) Correct。
按照我对OG中对现完的理解，如果在此用现完那么就意味着the first trenches cut into a 500-acre site at Tell Hamoukar这件事只能提供证据至今，而不能在将来继续证明后文的事实，这个逻辑上感觉不是很合理呀~~~~求解释