How is your quarantine going?

Given: circle a externally tangent to circle b. how many possible common tangents to circles a and b can exist? 2 3 4

The declining axolotl population in mexico city is an example of in overcrowded cities. a. the surpassing of support capacity b. changes to natural environments and native species c. the lack of safe homes and tenured spaces d. the effects of a growing urban heat island

Read the article about the fraser river, one of the most important rivers in canada. what is the most important species of fish in this river? why are the numbers of these fish declining?