Which of the following trees yields hard wood?

Which one of the following is used for preparing porcelain?

When a brick is immersed in water for 24 hours and then dried, if

Soundness of cement is tested by

The commonly used thinner in oil paints, is

Good quality stones must

The commonly used base for iron and steel work, is

Pick up the correct statement from the following:

Pick up the correct statement from the following: