Can someone help me to draw a use case and class diagram please

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.

According to this chart, which country is likely to have the most economic freedom with regards to entrepreneurship?

What has contributed to the growth of agriculture as big business in the midwest