Q: Which one of the following is NOT present in cement?
(a)2CaO·SiO2
(b)3CaO·SiO2
(c)4CaO·SiO2
(d)3CaO·Al2O3
Correct Answer: (c)
The correct answer is (c): 4CaO·SiO2. Subject: General Studies | Sub-topic: Miscellaneous Note: This answer was determined through AI-based research. Verify against the official answer key when available.