Anyone know why this is happening?

Using complete sentences, describe the central economic problem facing all humans. why does this require people to make choices? how can this result in opportunity costs?

The specific heat of the three substances in the image are given in the table. stamped concrete: 0.75, grass covered soil: 1.01, water: 4.18. place the areas in order based on how fast they’ll heat up on a sunny afternoon. start with the fastest and end with the slowest.

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!