Which of the following should be added to the plaster of Paris in order to increase its setting time?

The substance which is used for removing the excess material by means of cutting is called ________

Which of the following is not a property of a good electrical insulator?

Which of the following is not a hydrophobic admixture?

Tensile strength of leather belts should be about ___

Which of the following statements about gypsum is not correct?

Portland cement was invented by _______

Which of the following is not a synthetic resin?