15. another name for the interstellar matter that will eventually form a star is a. supernova b. red giant c. black hole d. nebular 16. in the milky way, the most abundant gas in emission nebulae is a. helium b. hydrogen c. argon d. nitrogen 17. massive star terminate in a brilliant explosion called a a. red giant b. protostar c. neutron star d. supernova 18. all stars, regardless of size, eventually a. turn into black dwarfs b. explode c. run out of fuel and collapse d. become black holes 19. the sun is a a. black hole b. black dwarf c. main-sequence star d. red giant

ans.

in united states (us), the first leading cause of death for both women and men is heart diseases that leads to more than half of the deaths. heart diseases develop due to narrow arteries, buildup of plaque in blood capillaries that arises difficulties in blood flow.

the second leading cause of deaths in us is cancer that affects individuals of all ages. it develops due to uncontrolled growth and spread of tumor cells, which results in death if the not controlled or treated.

the third leading cause of deaths in us is copd or chronic obstructive pulmonary disease. it includes difficulty in breathing, chest infections, and persistent cough. smocking is a leading cause of copd and around 80% of copd deaths occur due to smoking.

thus, the correct answer is 'option). cancer, copd, and heart disease.'