相当于省略了主语,如果补齐应该是more than three times as many independent institutions of higher education charge tuition and fees of under $8,000 a year as those charge over $16,000. 之所以选D不考虑其他选项是因为D是唯一有动词可构成对象平行的答案...
看错题发现自己把这道题想复杂了。其实很简单
studies采用MSR实验,大多数的动物对着镜子只会出现攻击行为,不会认出自己,但是大猩猩认出了自己。以此为依据,推理出了大猩猩是唯一的拥有 capacity for self-awareness 的nonhuman species.
这里的假设很简单,就是只能通过动物能不能在MSR中认出自己来判断它们有没有capacity for self-awareness
B选项正确,取非-如果一个动物没有MSR能力,它也有capacity for self-awareness ,很直接地削弱了结论(the great apes have a capacity for self-awareness unique among nonhuman species.)
对于这种有几个潜在先行词,且动词单复数存在讨论空间的选项,可以承认跳跃修饰的可能性