How is the mass number calculated for an element

Eastern europe and parts of northern europe have which of the following climates?

Complete the activity titled "comparative urban environments." every city is shaped by different cultural forces. in one to two paragraphs, contrast the culture of two different cities from this activity: new york and buenos aires. what makes these cities stand apart from each other culturally? what is unique about each city’s attitude, language, habits, foods, or architecture?

Plzz on what physical process is responsible for the creation of volcanoes, earthquakes and ocean trenches at the plate margins?