那让步起到的功能是什么呢?像刚才我提到的奇葩说的例子中“虽然对方辩友XXX说的很有道理”其实就是在承认对方观点的合理性(concede the validity of the opposing viewpoint )!
Some researchers contend that sleep plays no role in the consolidation of declarative memory (i.e., memory involving factual information). These researchers note that people with impairments in rapid eye movement (REM) sleep continue to lead normal lives, and they argue that if sleep were crucial for memory, then these individuals would have apparent memory deficits. Yet these tests could only clarify our understanding of the role of REM sleep, not sleep in general.
These researchers also claim that improvements of memory overnight can be explained by the mere passage of time, rather than attributed to sleep. But recent studies of memory performance after sleep make this claim unsustainable. Certainly there are memory consolidation processes that occur across periods of wakefulness, some of which neither depend on nor are enhanced by sleep. But when sleep is compared with wakefulness, and performance is better after sleep, then some benefit of sleep for memory must be acknowledged.
Which of the following best describes the function of the highlighted sentence?
(A) It provides the reasoning behind a claim about the role of sleep in memory consolidation.
(B) It explains why a previous claim about sleep and memory is unsustainable.
(C) It demonstrates why wakefulness is central to the process of declarative memory consolidation. E
(D) It emphasizes the limited role sleep plays in the process of declarative memory consolidation.
(E) It concedes that the consolidation of declarative memory does not depend entirely on one factor.
高亮句：Certainly there are memory consolidation processes that occur across periods of wakefulness, some of which neither depend on nor are enhanced by sleep.
首先通过“certainly”判定是让步逻辑;其次通过“neither depend on nor are enhanced by sleep” 可知是在限制睡眠的作用，因此可确定是作者通过让步承认对立面观点。因此答案为E 承认记忆的加强不完全依赖于一个因素(sleep)。
总结：让步会起到的另一个作用——explain why the following fact is surprising
To most geologists today, Wegener’s The origin of Continents and Oceans appears an impressive and prescient document, containing several of the essential presumptions underlying plate tectonics theory: the horizontal mobility of pieces of Earth’s crust; the essential difference between oceanic and continental crust; and a causal connection between horizontal displacements and the formation of mountain chains. Despite the considerable overlap between Wegener’s concepts and the later widely embraced plate tectonics theory, and despite the fact that continental drift theory presented a possible solution to the problem of the origin of mountains at a time when existing explanations were seriously in doubt, in its day Wegener’s theory was rejected by the vast majority of geologists.
The author of the passage refers to the “considerable overlap” (line 23) between continental drift theory and plate tectonics theory most probably in order to
(A) suggest that plate tectonics theory is derived from Wegener’s work
(B) introduce a discussion comparing the elements of the two theories
(C) examine the question of whether continental drift theory was innovative in its time D
(D) provide a reason why it might seem surprising that continental drift theory was not more widely embraced by geologists
(E) cite an explanation that has been frequently offered for Wegener’s high standing among geologists today
让步里说Wegener跟plate tectonics theory有很多相似之处，而plate tectonics theory是被广泛接受的理论，所以这会使得读者预期Wegener的理论也被接受才对，但是他是被拒绝的，所以就构成了一个怪事。因此答案为D。