Scientists are currently trying to look for evidence of life on other planets, specifically mars. one sign of life (like our own) is the presence of water. what elements would you look for on mars to see if we, as humans, could ultimately survive there?

choose one or more:

a. oxygen

b. carbon

c. hydrogen

d. calcium

e. nitrogen

the correct options are A(oxygen) and E ( Nitrogen).

Explanation: As humans we are able to survive in the planet earth due to its atmospheric composition. The Earth's atmosphere is composed of

Nitrogen(78%) and oxygen (21%). Currently, scientist from NASA has discovered existence of water in Mars. The elements they would look out for on Mars to see if we, as humans, could ultimately survive there is Nitrogen and oxygen.

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.