参考答案:"faults"
断层。在最后一段中"What we’ve found in springs like this by doing the DNA analysis is that the microbes that are coming up these faults are much more like what we find at mid-ocean ridges than like the rivers and streams we could expect in the continental setting."在泉水中找到的微生物通过DNA的分析检测出断层,这与我们所预想的大陆地面上的河流以及湖泊中的微生物不一样,但却更靠近海洋中央山脊上的微生物。v. 扩大,增大