将下面三段话翻译成汉语,并体会专业英语的特点。 Polymer dispersions can also often be precipitated and purified by pouring them into methanol, by adding methanol, or by cooling the dispersion in some kind of a cooling mixture (-20°C to -40°C). Since methanol is miscible in all proportion both with benzene and with most other organic solvents and also with water, it can be used as a precipitant in both cases, i.e., with organic and with aqueous polymer solutions. The separation of different macromolecular compounds which are present in the mixture is particularly difficult.