The high-temperature performance of silica refractories is compromised by the presence of even small concentrations of alumina (Al2O3).

For composite materials, which is phase is normally harder?

Which of the following cement materials is consumed in the largest tonnages?

Which of the following is a definition of glass transition temperature?

For crystalline ceramics, plastic deformation occurs by the motion of dislocations.

Which of the following are NOT properties required for abrasive ceramics?

Which of these polymers are most resistant to attack by chemicals, and, as such, are often used as coatings?

Plastics may be which of the following?

def compute_values(a, b, c):    yield a + b    yield b * c    yield (a + b + c) / 3gen = compute_values(2, 4, 6)for value in gen:    print(value) What is the output of this snippet of code?

class forest:  def __init__(self, trees):    self.tree = trees  def grow(self, leaves):    for leaf in leaves:      self.tree.extend(leaf)  def dry(self, heat):    for h in range(heat):      self.tree.pop() f = forest([“elm”, “birch”, “maple”])f.grow([“oak”, “spruce”])f.dry(4)print(f.tree[5]) Which of the following is the correct output of the above code?