Answer:
c) Combustion of fossil fuels
Explanation:
Burning of fossil fuels is the main cause of increasing carbondioxide concentration in the environment which results in air pollution. This increase in carbondioxide concentration absorbed more heat energy from reflected solar radiation which increases the temperature of earth surface causes global warming. Due to this global warming, snow melting occurs on the poles of the earth which increases sea level.
Answer:
The correct option is B (natural killer cells).
Explanation:
Natural killer cells: They are defined as the type of cytotoxic lymphocyte which are critical to the innate immune system. The NK cells play an important role in to provide rapid response to tumor formation, virus infected cells, and acting after three days of infection.
While cancer cells die, they release some antigens, than these antigens are recognized by the immune system, and later they are presented on the immune cells which are known as antigen presenting cells. So, if these cells are absent than they increase the chances of developing malignant tumors.
Given that Sheena's ball is a sphere, its volume can be obtained by using the formula: V_ball = (4/3)*pi*r^3, where, r is the radius of the sphere. Since the ball is 24 cm across, this means that the radius is half of the diameter which is equal to 12 cm. Thus, the volume of the ball is equal to 7238.2295 cm^2.
