Preposition Germ Warfare Chapter 2

Germs Warfare Charpter 2
Because we germs are so microscopic _____ size, _____ many years humans did not understand why they became sick, or how sickness was spread _____ one person to another. Although humans learned that they could become ill _____ eating bad food, drinking unclean water or touching other sick humans, they did not know why.
The war against us was impossible to win because oue enemy did not know who or what they ere fighting. Our secret weapon was our smallness, our invisibility to the human eye. Without understanding how we spread or where we lived, humans could not come _____ with proper strategy, or battle plan to fight us.
Humans have long known about plants that could be used as medicines to cure some disease, but they did not understand how they worked against us. Often, people who were taken to hospital became even unwell, because doctors did not know that germs were waiting _____ thier skin, _____ the air that they breathes, and _____ their medical instruments.
Our germ soldiers were everywhere, ready to strike! Then , one day in 1676, one of our secret grms armies was discovered. A Dutchman called Anthony Van Leeuwenhoek invented a magnifying glass which made things seem bigger than they really were. He looked _____ his magifying glass at a drop of dirty rainwater.
This dsicovery was vital _____ the war against us. At last, humans began to understand what they were fighting. Slowly, humans began to realise that we were everywhere. Finally, they discovered that some kinds of bacteria caused people to become sick. They called us germs. Having identified their enemy, humans started to look _____ ways to attack us. It was about to become a difficult time _____ we germs!