Medical, Psychiatry, Biology, Geography, etc,
they are full of jargons, technical terms and terminology in the texts, and may not have any equivalent yet in other languages, including Chinese, translator may have to create one that best match the source word. Moreover no software is powerful enough to translate fluently so far, and require the translator to restructure the sentences in target language in a manner and expressions that native readers normally read. Hence it takes more time to translate them to be understood by the native reader in the target language, as such the rates per word are usually higher than normal text.
…….more to come when ready