Is a superheated cloud of gas and dust swirling around a massive object (usually a neutron star or black-hole). This cloud can reach incredible speeds and temperatures as gravity causes the gas and dust to rub together and eventually glow with x rays. a. Nebula
c. Accretion disk
b. Proto-star
d. White Dwarf

explanation:

venn diagram is pictorial representation with of circles showing the relation between two finite sets or things. the intersection part of two circles conveys the relation present in between those sets or things.

here in the venn diagram of sand and salt two circles represent sand and salt. but the area falling under the intersection of these circle represents the mixture of sand and salt.

so, in a venn diagram the mixture will be placed in a middle that is in between the intersection of two circles.

o conteúdo de calor de um sistema é igual à entalpia apenas para um sistema que é constante