Which of the following is an example of a covalent crystal solid?

Select the correct statements.
$(A)$ Crystalline solids have long range order.
$(B)$ Crystalline solids are isotropic.
$(C)$ Amorphous solids are sometimes called pseudo solids.
$(D)$ Amorphous solids soften over a range of temperature.
$(E)$ Amorphous solids have a definite heat of fusion.
Choose the most appropriate answer from the options given below:

Crystals of which pair are isomorphous?

What is a domain in the context of magnetism in solids?

Which of the following possesses a layered crystal structure?

Which property is not typical of a refractory material?