How are white dwarfs and neutron stars similar?

a. they are both main sequence stars.

b. they are both left over after a star has died. a white dwarf is left over from the death of a low-mass star and a neutron star from the death of a high-mass star.

c. white dwarfs are made of carbon, and so are neutron stars.

d. they both will explode in a supernova when they have died.

The rate at which molecules water and oxygen can enter a cell is determined by the-

1. emigration the movement of people from one place to another 2. immigration a situation in which resources are being used up at a faster rate than they can be replenished 3. migration the leaving of one's homeland to settle in a new place 4. overpopulation the movement of people to a new country 5. sustainable development a situation in which the birth rate is not sufficient to replace the existing population 6. underpopulation the ability to meet current needs without reducing the ability to meet future needs 7. unsustainable development the increase in the population of a city 8. urbanization a situation in which the number of people exceeds the available natural resources in an area

Explain the significance of thesaurus geographicus