The Mount Sinai researchers also warned against, Bisphenol-A, a substance present in many food containers, plastic water and baby bottles (indicated by a number 7 printed on the base).

Finally, we point out: the essence of landmark building is the image in the image of city by the substance and space, and its expression is base on a good urban design.

In the form of a water solution or as litmus paper, it is the oldest and most-used indicator of whether a substance is an acid or a Base.