Question

ぽぽ

(1)は、和訳をするとどうなりますか？
itの意味を明確にと書いてありました。

22 Bolivia* has a far greater variety of languages than all the countries of Europe combined,
but they are increasingly threatened by dominant languages such as Spanish. In Bolivia,
Harrison met with people who have used certain plants as medicine since the time of the Inca
Empire*. Besides a common local language, they also maintain a secret language to name
thousands of plants used as medicines, some unknown to science.
3 (When a language is lost, centuries of human thinking about such things as animals and
plants may be lost with it. Eighty percent of existing species have not yet been discovered

Answer 1

taka

(1) <When(接続詞) a language(S1) is(V1) lost(C1)>, centuries of human thinking(S2) (about such things)(M) (as [animals] and(等位接続詞) [plants])(M) may be(V2) lost(C2) (with it)(M).
＜ある一つの言語が失われる時＞、[動物]や[植物]のようなものについて何世紀も人間が考えたことも、その言語と一緒に失われるのかも知れない。
※centuries(複数) of …　何世紀もの…　　such A as B BのようなA　　it=単数 → itの前にある単数形の名詞を探す → a language(言語)

参考にしてください。