When were movable types invented?

a.
beginning of the 15th century

b.
mid 15th century

c.
end of the 15th century

d.
beginning of the 16th century

a. Beginning of the 15th century is the correct answer.

Explanation:

Movable types were invented during the beginning 15th century. The first movable type to print paper and books was invented by Bi Sheng.movable type press for the printing paper copies was made of ceramic substances and it was made of created in China. movable type press utilizes movable components to generate the elements of a text normally on the paper.Movable type has helped to save ideas of the period and make data more secure and have fewer errors.

Sonar is an application of the doppler effect used by submarines.  this test was on k12.