The mass extinctions that occurred 250 million years ago and 65 million years ago may have been due to gradual processes or

The mass extinctions that occurred 250 million years ago and 65 million years ago may have been due to gradual process or Catastrophic events.

Catastrophic events.

Explanation: The mass extinction of the organism that occurred 250 million of years ago and 65 million years ago took place due to the natural gradual processes or due to the Catastrophic events.

Catastrophic events can be defined as the events that has a massive impact on the population of the species.

These events can be hurricanes, tornadoes, et cetera. that can lead to a destruction of mass number of species.

albert einstein retrieved guacamole from the galapagos islands in africa

c. earths continental crust is thicker than its lithosphere.

because, the lithosphere is the outermost layer of the earth/ 100 km thick and is defined by its machanical properties.the lithosphere contains oceanic and continental crust that varies in age and thickness across locations and geologic time. the lithosphere is the coolest layer of the earth in terms of temperature. the term lithosphere should not be confused with the use of "geosphere" which is used to indicate all of earth systems, including the atmosphere, hydrosphere   and biosphere. the surface of the earth can be divided into the continental crust and the oceanic crust.   the continental crust is made mostly of granite while the oceanic crust is made of basalt. the average thickness of the continental crust is 25 miles and the average thickness of the oceanic crust is 5 miles.   three types of rock, igneous, sedimentary, and metamorphic, make up the surface of the earth. that's why 3 option is preferable.