49 According to the passage, what kind of study plays a major part in helping us understand the history of the Indo-Europeans?
(A) A study of prehistoric plants
(B) A study of prehistoric deities
(C) A study of prehistoric climate
(D) A study of prehistoric languages

Linguists語言學家 subscribe訂閱，訂購（產品） to the belief that the languages of about one-third of the human race all developed from one Indo-European language印欧语系.

But who were the speakers of this ancient古代 language? Linguistic detective work offers主動提出；提議 some clues: you can deduce推斷 a people’s history from the words they use.

Study of some fifty ancient vocabularies has led to a reconstruction（對被毀的事物進行的）重建，改造 of the lifestyle of the first Indo-Europeans, a vanished消失的；滅絕 people.

From the words they used ,it seems likely that they lived a half-settled, half-nomadic遊牧部落 existence存在；實有.

They worshipped敬奉，崇拜 gods who are clear ancestors祖先 of Indian, Mediterranean地中海, and Celtic deities.

However, exactly who the original Indo-Europeans were and when they lived remain a hotly debated談論，討論 mystery.

According to an early theory, they lived in Mesopotamia, but this idea was exploded by nineteenth-century archaeology考古學.

Today, some argue for the Krugan culture of the Russian steppes（尤指東南歐、俄羅斯和亞洲北部無樹的）乾草原, others for the farming culture of the Danube valley.

The most widely accepted theory locates the Indo-Europeans in a cold, northern climate where common words for snow and wolf were important.

None of these prehistoric史前 languages had a word for the sea.

From this, and from our knowledge of nature, it is clear that the Indo-Europeans must have lived somewhere in northern central Europe.

plant翻譯：生物體, 植物, 建築物／機器, 機器，設備, 工廠, （用於修路等的重型）設備， 裝置，機械, 偷偷放置, 栽贓物品, 生物體, 種植，栽種, 在…處栽種植物, 放置, 放置

Deity (1) 神明；神性；神祇 對造物主較抽象的稱呼