Answer:
First drop down
A threat to their daily life
Second drop down
A spread of contagious disease from settlers
Explanation:
European explorers came to North America in the 1500s on their voyage and trips around the world.
They met the American Indians who were great hunters and survivors already living there.
This place was a new place to the European explorers as they met people they haven't met before, heard different strange languages and had encounter with an entirely different culture from what they knew or were used to.
The American Indians were suspicious of the Europeans immediately they set foot in Northern America.
These explorers brought with them strange diseases like small pox, influenza and measles that the natives had no immunity to and therefore vulnerable.
These diseases killed the American Indians in great numbers, killing about 90% of the population because the natives did not know what the disease was nor the remedy.
Soon after, the European colonists began to do trade by barter, with the natives offering prepared animal meat for pieces of clothing and sometimes guns and gunpowder.
The Europeans soon made the natives their slaves.