Which term refers to american troops in europe during world war 1

Cavalrymen used the term to deride foot soldiers, because the brass buttons on their uniforms looked like the flour dumplings or dough cakes called "doughboys", or because of the flour or pipe clay which the soldiers used to polish their white belts.

aug 15, 2012 - although van leeuwenhoek was not the inventor of the microscope, he advanced it more he loved to grind and focus a new lens in order to see the unseen world. most of leeuwenhoek's microscopes were silver. in a simple but significant experiment (1668), he demonstrated that worms found on

a social contract.

"a social contract is an agreement between citizens and their leader where the citizens give up certain freedoms in exchange for protection. the constitution of the united states is an example of a social contract."