1: Which is not a mechanism for plate movement A. slab pull

B. ridget push

C. convection

D. mid-ocean ridget

2:which agriculture technique is the least economical sustainable

A. cultivating only one species of plant in each farm

B. using reduced or ni tilling of soil

C. using manure to fertilize soil

D. rotating different crops or livestock on a ply of land

3: how can agriculture negatively impact the environment
A. it can increase the amount of flooding

B. It releases carbon dioxide into the atmosphere

C. Agriculture reduces the amount of oxygen in the atmosphere

D. Farmers use fertilizers and pesticides which can contaminate rivers and streams

D.rotating different crops or livestock on a ply of land

C. Agriculture reduces the amount of oxygen in the atmosphere

Explanation:

primary succession occurs in essentially lifeless areas regions in which the soil is incapable of sustaining life as a result of such factors as lava flows, newly formed sand dunes, or rocks left from a retreating glacier. secondary succession occurs

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.