Misc: what effect do doctors produce by stroking the sole of the foot?

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?