12-13 rubhub 修改的答复如下:
We left a beaker of copper sulphate solution on the lab bench.After three weeks,copper sulphate began to precipitate out of the solution,depositing solid blue crystals on the dangling thread and on the glass walls.Later,we found more blue crystals at the bottom of the beaker,along with some sediments.
在这里,precipitate = 结为晶体
deposit = 凝附在
sediment = 沉积物
用在天气预报时候precipitation 专指水气变相,凝成雨露冰霜雪,例如 There is a 100% chance of precipitation.= 降雨(雪,冰雹,)可能性达到百分之一百.
...precipitate...适用于:
物质变相时候.
...deposit...适用于:
物质变相时候,特别是
变相然后凝附到一个表面上时候
没有变相,单纯因自身重量而下沉,堆积的时候
矿藏
...sediment...适用于:
单纯沉积,并没有变相.或是说话时不理会物质有没有变相.
往往指不纯粹的东西,杂质,废料等.
这三个词的词性也有不同,如下:
precipitate 动词 precipitation 名词
deposit 动词兼名词
sediment 名词
应用:
When we seed the clouds with silver iodide,rain is precipitated.碘化银撒进云层裏能造雨.
Today,had we not seeded the clouds there would have been no precipitation.假若今天不是撒了碘化银的话,肯定不会下了这场雨.
Crystallized products are deposited on the bottom of the vessel.晶体凝附到容器底部.
The lightest particles are deposited last.重量最轻的颗粒最迟沉积.
The South China Sea has rich deposits of petroleum and gas.中国南海有蕴藏量极丰富的石油、天然气.
Fine,sandy sediment can be found here and there at the southernmost front of the glacier.幼沙沉积层散见於冰河南端.
