一、英譯中：請將下面這段英文譯成正確、流暢的中文（30 分） Language evolution can be compared to biological evolution, but whereas genetic change is driven by environmental pressures, languages change and develop through social pressures. Over time, different groups of early humans would have found themselves speaking different languages, and then, in order to communicate with other groups – for trade, travel and so on – it would have been necessary for some members of a family or band to speak other tongues. In fact, multilingualism has been testified to have many social, psychological and lifestyle advantages. However, we are now living in a world that is losing languages faster than ever, at the current rate of one a fortnight, and with the prospect that half our languages will be extinct by the end of the century.