Questions

The llama, its wild cousin , the Vicuna and hump-less Alpaca are also found in the high pasture lands of the Andes region of Bolivia and peru, where they are useful as beasts of burden and for the production of fleece and meat.

In 1985 the physicist Wilhelm Rontgen discovered X-rays, the "X" signifying their unknown origin.He later found that the rays could pass through flesh and by using photographic plates could make images of bones inside the body. 

Envelope is a letter holder for one letter and in the question it mean that it holds one letter. Eye is also a word which starts and end with E but has one letter in the middle.