【英语时差8,16】泥土的味道

A lot of people love that fresh-dirt smell. The surprising thing, though, is that it isn’t coming from the dirt itself. Microbiologists have traced the pleasant odor to an organic chemical called “geosmin.” A microbial geneticist named Keith Chater at the John Innes Center in England has traced geosmin down to a common bacterium² called Streptomyces coelicolor. He even found out exactly which gene¹ in the little critters causes them to produce geosmin. Interestingly enough, there are unconfirmed reports that animals are attracted to fresh dirt in the desert, and go there looking for water. As they nose around the dirt, they pick up plenty of S. coelicolor, which then hitch³ a ride from one oasis⁴ to the next. If it’s true, then the bacteria in general may create the odor in order to attract animals. The animals find water, the bacteria are spread, and everyone is happy.

1 gene   

n.遗传因子，基因

参考例句：

• A single gene may have many effects.单一基因可能具有很多种效应。
• The targeting of gene therapy has been paid close attention.其中基因治疗的靶向性是值得密切关注的问题之一。

2 bacterium   

n.(pl.)bacteria 细菌

参考例句：

• The bacterium possibly goes in the human body by the mouth.细菌可能通过口进入人体。
• A bacterium is identified as the cause for his duodenal ulcer.一种细菌被断定为造成他十二指肠溃疡的根源。

3 hitch   

v.免费搭(车旅行)；系住；急提；n.故障；急拉

参考例句：

• They had an eighty-mile journey and decided to hitch hike.他们要走80英里的路程，最后决定搭便车。
• All the candidates are able to answer the questions without any hitch.所有报考者都能对答如流。

4 oasis   

n.（沙漠中的）绿洲，宜人的地方

参考例句：

• They stopped for the night at an oasis.他们在沙漠中的绿洲停下来过夜。
• The town was an oasis of prosperity in a desert of poverty.该镇是贫穷荒漠中的一块繁荣的“绿洲”。