UnScramble this Word: o g e a r n l i?

Questions

Which natural phenomenon can be measured on the Mercalli scale?

Tests on drugs and poisons determine the LD-50 dose. What does LD stand for?

What is the correct name for brown coal?

What material features in the construction of a "corduroy road"?

Of which country was Faisal, assassinated in 1975, king?