Which of the following is the quickest to react with water when the water is added to the cement?

The thermo-plastic glues are permanent once they are set.

Tensile strength of leather belts should be about ___

Which of the following is not a natural abrasive?

Total sulphur content in the cement should not be more than _____

Which of the following oils are obtained by mixing mineral oils with animal or vegetable oils?

The coefficient of heat conductivity of heat-insulating materials does not exceed _____

Calcium sulphate is present in ordinary cement in the form of ______