chemical中等

(49) The volatile chemicals produced by plants can be carried a long way, and they are very characteristic: Each plant or tree has its own particular odor signature.

（49）植物产生的挥发性化学物质可以传播很远，而且非常有特点：每种植物或树木都有其独特的气味标识。

They infused some with stabilizing and consolidating chemicals.

他们给其中一些注入了起稳定和加固作用的化学物质。

Van Oosten calls those chemicals “sunscreens” because their goal was to prevent further light damage and rebuild worn polymer fibers.

范·奥斯滕把这些化学物质称为“防晒霜”，因为它们的目的是防止进一步的光照损害，并重建磨损的聚合物纤维。

For H&M to offer a $5.95 knit miniskirt in all its 2,300-plus stores around the world, it must rely on low-wage overseas labor, order in volumes that strain natural resources, and use massive amounts of harmful chemicals.

H&M要在其全球2300多家门店里出售一条5.95美元的针织迷你裙，就必须依赖低工资的海外劳动力，以让自然资源不堪重负的规模下订单，并使用大量有害化学品。

Britain has relatively few butterfly species compared with mainland Europe and 80% are in decline, mostly because intensive chemical farming has reduced many species to tiny fragments of habitat and small nature reserves.

与欧洲大陆相比，英国的蝴蝶种类相对较少，而且其中80%正在减少，这主要是因为集约化的化学农业使许多物种只能栖身于零星的小块栖息地和小型自然保护区。

Throughout the trip, Jackson juggled multiple cameras and plate sizes using the “collodion process” that required him to coat the plates with a chemical mixture, then expose them and develop the resulting images with a portable darkroom. The crude technique required educated guesses on exposure times, and involved heavy, awkward equipment — several men had to assist in its transportation. Despite these challenges, Jackson captured dozens of striking photos, ranging from majestic images like his now-famous snapshot of Old Faithful, to casual portraits of expedition members at the camp. While veterans of previous expeditions wrote at length about stunning trail sights, these vivid photographs were another thing entirely.

在整个旅途中，杰克逊使用“火棉胶工艺”同时摆弄多台相机和多种尺寸的底片，这种工艺要求他先给底片涂上一层化学混合物，然后曝光，再用便携式暗室冲洗出影像。这种简陋的技术需要凭经验推测曝光时间，而且所用设备笨重难使——需要好几个人协助搬运。尽管困难重重，杰克逊还是拍下了几十张引人注目的照片，从他那张如今已闻名于世的老忠实泉快照这样的壮丽画面，到营地里考察队员的随意肖像，不一而足。以往考察的老手们曾长篇累牍地描写沿途的壮丽景色，而这些生动的照片则完全是另一回事。