So don't take the telephone for granted, but keep in mind that our modern way of life is mainly due to its invention.

take 在这里是动词，意思是"认为、看待"。 for 是介词，在这里与 take 构成固定搭配，表示"把...当作..."。 granted 是动词 grant 的过去分词形式，grant 的意思是"给予、承认"。take...for granted 是固定短语，意思是"认为...理所当然"。 take...for granted 这个短语表示把某事物视为理所当然、不加思考地接受。