美国科学60秒 SSS 2013-07-10
时间：2019-01-20 作者：英语课 分类：Scientific American(七)月
英语课
Lawn enthusiasts 1 love a lush, green carpet of grass, which is why they hate crabgrass. And now, they may have one more reason to despise the weed. Because crabgrass isn't just faster-growing than the rest of the lawn. It may actually be poisoning the lawn, by pumping herbicide into the soil. That's according to a study in the Journal of Agricultural and Food Chemistry.
Researchers grew crabgrass hydroponically, so they could easily capture any chemicals released by the plant's roots. Then they dripped that hydroponic solution into pots of wheat, corn and soybean seedlings 2. Two weeks later, they dried and weighed the seedlings. And sure enough, the crabgrass solution had significantly stunted 3 the seedlings’ growth, compared to control plants. And since corn is in the same family as lawn grasses, the crabgrass toxic 4 effect may also spell bad news for your beautiful Kentucky bluegrass.
The researchers still aren't exactly sure how crabgrass' chemical weapons work. But the weed can wipe out beneficial bacteria and fungi 5 in the soil too. So it’s possible that crabgrass poisons its neighbors directly, by releasing toxins 6, and indirectly 7 by creating inhospitable soil. Either way, it's bound to make lawn owners crabby.
n.热心人，热衷者( enthusiast的名词复数 )
- A group of enthusiasts have undertaken the reconstruction of a steam locomotive. 一群火车迷已担负起重造蒸汽机车的任务。 来自《简明英汉词典》
- Now a group of enthusiasts are going to have the plane restored. 一群热心人计划修复这架飞机。 来自新概念英语第二册
n.刚出芽的幼苗( seedling的名词复数 )
- Ninety-five per cent of the new seedlings have survived. 新栽的树苗95%都已成活。 来自《现代汉英综合大词典》
- In such wet weather we must prevent the seedlings from rotting. 这样的阴雨天要防止烂秧。 来自《现代汉英综合大词典》
adj.矮小的；发育迟缓的
- the stunted lives of children deprived of education 未受教育的孩子所过的局限生活
- But the landed oligarchy had stunted the country's democratic development for generations. 但是好几代以来土地寡头的统治阻碍了这个国家民主的发展。
adj.有毒的，因中毒引起的
- The factory had accidentally released a quantity of toxic waste into the sea.这家工厂意外泄漏大量有毒废物到海中。
- There is a risk that toxic chemicals might be blasted into the atmosphere.爆炸后有毒化学物质可能会进入大气层。
n.真菌，霉菌
- Students practice to apply the study of genetics to multicellular plants and fungi.学生们练习把基因学应用到多细胞植物和真菌中。
- The lawn was covered with fungi.草地上到处都是蘑菇。
n.毒素( toxin的名词复数 )
- The seas have been used as a receptacle for a range of industrial toxins. 海洋成了各种有毒工业废料的大容器。
- Most toxins are naturally excreted from the body. 大部分毒素被自然排出体外。 来自《简明英汉词典》
adv.间接地，不直接了当地
- I heard the news indirectly.这消息我是间接听来的。
- They were approached indirectly through an intermediary.通过一位中间人，他们进行了间接接触。