b. The ground support of the boiler
e. 2, 4
a. 1, 2, 4
c. downwards
b. drum
a. temperature
d. major
c. foundations
b. drum
a. expansion
c. casing
a. Refractory
d. castables
b. outer
b. seamless
a. cold
c. Seamless
d. lengthen
c. burnishing
b. extrusion
d. curvature
a. seams
a. True
b. hot