Wouldnt it be great if we could trade genes with other species? For example, suppose you could trade the family cat your genes for intelligence for its genes for physical coordination! Well, okay, thats not likely to happen anytime soon. But DNA trad

发表于:2018-12-31 / 阅读(68) / 评论(0) 分类 英语听力文摘 English Digest

Woodpecker s and Fungus 啄木鸟和真菌 W: Woodpecker s puncture the bark of dead or dying trees, also known as snags, to find the wood-boring insects that make up their diet, and some species also excavate cavities in these trees for their nests.

发表于:2019-01-26 / 阅读(62) / 评论(0) 分类 英语听力文摘 English Digest

Dirty Hands 洗手误区 Most people believe that regular hand-washing is the best way to prevent infection s . And theyre right: hand-washing does prevent certain infection s , but too much washing can actually help some infection s along.Whats goin

发表于:2019-02-24 / 阅读(48) / 评论(0) 分类 英语听力文摘 English Digest

Fencing in Bacteria 绿脓杆菌(p.aeruginosa)或称铜绿色假单胞菌,是一种致病力较低但抗药性强的杆菌。广泛存在于自然界,是伤口感染较常见的一种细菌。能引起化脓性病变。感染后因脓汁和渗出

发表于:2019-02-24 / 阅读(63) / 评论(0) 分类 英语听力文摘 English Digest