那么在此题中，they have a heat-exchange network that keeps the brain from getting too hot. 是否表示食肉动物除了有这种热交换系统以外，还拥有另一种热交换系统，这种热交换系统不具有冷却大脑的功能？ 但这样显然不合逻辑阿？？是不是应该用非限制性定于从句来说明食肉动物的热交换系统都有使大脑冷却的能力？
OG12-10题目是这样的：
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.
(A) which kept (B) that keeps (C) which has kept (D) that has been keeping (E) having kept The correct answer is B.
看OG10-141这道题
141.Unlike transplants between identical twins, whose genetic endowment is the same, all patients receiving hearts or other organs must take antirejection drugs for the rest of their lives.
(A) Unlike transplants between identical twins, whose genetic endowment is the same
(B) Besides transplants involving identical twinswith the same genetic endowment
(C) Unless the transplant involves identical twins，who have the same genetic endowment
(D) Aside from a transplant between identical twins with the same genetic endowment
(E) Other than transplants between identical twins,whose genetic endowment is the same
In A and B, the phrases beginning Unlike... and Besides... modify patients, the subject of the main clause; thus A absurdly states that Unlike transplants ..., patients... must take ... drugs, and B that all patients except for transplants... must take ... drugs. In B and D the expression identical twins with the same genetic endowment wrongly suggests that only some identical twin pairs are genetically identical. In E, the construction Other than transplants..., all patients ... must take... drugs illogically suggests, as in B, that some patients are transplants. Choice C, the best answer, solves these problems by using a clause introduced by Unless to describe the exception to the rule and a nonrestrictive clause beginning with who to describe the characteristic attributed to all identical twins. 这道题的官方解释里面说，identical twins不能用限制性定于从句来修饰，如BD，因为BD隐含的意思是说还有别的一些的twins都不具有same genetic endowment这个性质。但实际上所有的identical twins都有这个性质的。所以这题只能用C中的非限制性定于从句。 作者: ope 时间: 2009-12-10 12:51
自己写完以后又有了新的理解。OG12-10官方解释中说要用限制性定语从句，是不是要说明“还有一部分热交换系统不都能使大脑冷却”。而不是“还有一部分食肉动物的热交换系统不都能使大脑冷却”？
如果是这样理解的话，那么在以后的做题中怎么确定定语从句的修饰范围呢？作者: sayysong 时间: 2009-12-10 16:43
... they have a heat-exchange network that keeps ... 这里的that就近修饰network，所以是“还存在其他的一些热交换系统”，而不是“其他的食肉动物”。 把定语从句拿掉只剩先行词，看看意思能否表达完整无歧义，能，则是非限制性定语从句，不能，则是限制性定语从句。而这个“意思能否表达完整无歧义”，就得联系前后句来理解了，所以还是逻辑意思是王道啊～作者: ope 时间: 2010-3-4 13:51
嗯，把定语从句拿掉再看逻辑意思是否正确，这个方法好像不错。可操作性强。