120 students in a fifth grade class are surveyed about what kinds of pets they have. Of the 120 students, 30 have a goldfish, 40 have a mouse, and 10 have a goldfish and a mouse. Using this information, answer each of the following questions. Are these 2 events mutually exclusive ?

Drastic boundary changes can occur for all of the following reasons except for a. a shift in the way a river flows b. the collapse of a government system c. a conflict between two neighboring groups d. one country's decision to sell land to another country select the best answer from the choices provide

Explain why components that are naturally found in air can be considered air pollutants.

Which of the following east asian contries are a peninsula? a. china b. taiwan c. south korea d. mongolia