Why don’t we have eclipses every month?

Creation of an unnaturally uniform sample to represent a diverse populationcan be avoided by: a. including only willing b. asking another scientist for .c. choosing only identical participants.d. selecting individuals at random.

Aheterozygous normal male marries a woman with a sickle cell anemia. give the genotypes and possible phenotypes of the offspring

In "the man in the water," what was the remarkable occurrence that rosenblatt reported?