Please help for questions 11 and 12 I will give you BRAINLIEST for the correct answer

How are the high islands of the pacific formed? a. by connected coral reefs called atolls b. by lagoons c. by moving glaciers d. by underwater volcanoes

Why have the countries of the region had difficulty establishing democratic governments in recent years? choose all answers that are correct b is also correct i need to know if theres any morecommunists have overtaken the countries of the caucasus region. the soviets established national borders in the region without considering the location of ethnic groups. fighting continues between armenia and azerbaijan over the nagorno-karabakh region. civil war between communists and islamic groups in tajikistan resulted in thousands of deaths and refugees are forced to flee. in a test!

In the diagram below, ab and bc are tangent to o. what is the measure of