Engineers began to stabilize the Leaning Tower of Pisa between 1990 and 2008 AD. How?
Hundreds of people are holding it up day and night.
It has lots of suspension cords holding it up.
A crane pushed the top of it upright.
Ground was slowly removed from underneath one side of the tower.

24-karat gold is considered to be pure gold. 18-karat gold is considered to be about 75% gold. what is 18-karat gold considered a mixture rather than a pure substance? a) it has a variable composition of other elements and minerals. b) its color is different than pure gold. c) the gold atoms are not arranged in a repeating pattern. d) it can be melted and transformed into a different substance.

Why is james madison significant in regards to the bill of rights?

What is generally true of the lower house in a state legislative branch ?