Phagocytes are the Leukocytes that respond to nonspecific foreign invaders. While Lymphocytes respond to specific invaders. These are components of the blood that are triggered by the immune system when invaders (e.g. bacteria, virus) enter the body. Without these components in the blood, the body will not be able to protect itself from numerous diseases. These are major defense mechanisms of the body.
Answer:
The correct answer is <em>D) wood block printing and movable type</em>
Explanation:
Before the invention of wood block printing, books were written by hand. Each expert wrote the pages manually and it could take days and weeks to complete one book.
Hence, books were expensive and only affordable for a few. However, with movable type, it was possible to print new books quickly. The prices decreased and there was a boom in scholarship and education.
Old Faithful geyser in Yellowstone
