GUNPOWDER, IN SOME WAYS THE MOST EFFECTIVE OF ALL THE EXPLOSIVE M...
312. Gunpowder, in some ways the most effective of all the explosive materials,
were a mixture of potassium nitrate, charcoal, and sulfur.
a. in
b. all the
c. were
d. of
--> c
312. Gunpowder, in some ways the most effective of all the explosive materials,
were a mixture of potassium nitrate, charcoal, and sulfur.
a. in
b. all the
c. were
d. of
--> c