The gypsy moth is now one of the most challenging insect pest species in north america. with hundreds of known plant hosts, many of which are completely defoliated during outbreak years, the gypsy moth has no shortage of food and defoliation lasting two or more years can cause significant tree mortality. today this introduced species is considered an invasive species. the gypsy moth became established in the u. s. for all but one of the following reasons. a) female gypsy moth egg masses may contain over 1,000 eggs. b) females cannot fly so it may take longer for the species to reach surrounding areas and flourish. c) the caterpillars that hatch from eggs are capable of feeding on over 300 species of trees and shrubs. d) predators, parasitoids, and diseases that would feed on the egg masses in its native habitat are not present.

in 1972 the fluid—mosaic membrane model of membrane structure was proposed based on thermodynamic principals of organization of membrane lipids and proteins and available evidence of asymmetry and lateral mobility within the membrane matrix [s. j. singer and g. l. nicolson, science 175 (1972) 720–731].

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.