What is the summer caused by? Earth's closeness to the sun

indirect sunlight striking Earth

Earth's far distance from the sun

direct sunlight striking Earth

It has to be b i hope this

Ch4 and ph3 are both covalent since they are composed both of non-metals.    ch4 is non- polar because of  london forces and has a geometry of tetrahedral  ph3 , on the other hand, is umbrella shaped polar and has dipole-dipole intermolecular force (imf) . since ph3 is polar, it has a stronger imf