Why don't we see a lunar eclipse every month during the full moon?

Aplane takes off from an airport and flies to town a, located d1 = 215 km from the airport in the direction 20.0° north of east. the plane then flies to town b, located d2 = 230 km at 30.0° west of north from town a. use graphical methods to determine the distance and direction from town b to the airport. (enter the distance in km and the direction in degrees south of west.)

Pls pls pls pls ! describe, in your own words, how you found the epicenter of the earthquake.

Which is not true about oxygen-17 and oxygen-18?