Asbjørn 'Bear' Riis, Danish professional wrestler
Bjarne Riis (born 1964), Danish former professional road bicycle racer, now the team owner and manager of Danish UCI ProTour outfit Team CSC
Fredrik Riis (1789-1845), Norwegian county governor
Jacob Riis (1849-1914), Danish-American muckraker journalist, photographer, and social reformer
Nelson Riis (born 1942), businessman and former Canadian politician and New Democratic Party (NDP) Member of Parliament
Povl Riis, gastroenterologist
Answer:
I think its ans is option B
Answer:
Imbalance occur when the hydrogen of the star's core used up.
Explanation:
Both gravity (hydrostatic) and pressure (thermal) create an equilibrium state during star formation. A star is in the state of hydrostatic equilibrium when the pressure that is created due to core burning is in balance with the force of gravity. These two will be in equilibrium when the outer push of core is in equal amount to the inward push of gravity. When the hydrogen that is present in the star's core has been used up, burning stops, which leads to the imbalance of gravity and pressure. This imbalance the star which undergo significant changes in its shape and structure..