Which of the following chemical reactions are an example of a combustion reaction? Select all that apply.
O Gasoline powering a vehicle
( A solid forms when two solutions are mixed
O Water breaking down
Gunpowder firing a bullet from a gun

im not exactly sure but i think its b!

some sources quote the lethal dose, for an average 170lbs opiate-naive individual is between 75 and 375 mg

a gas, having a molecular weight of 13 kg/kmol and a kinematic viscosity of 0.25 cm2/s, flows through a pipe 0.25 m internal diameter and 5 km long at the rate of 0.4 m3/s and is delivered at atmospheric pressure.