What religion did french missionaries introduce to vietnam?

Me asap with these two questions about wwi 20 points will be rewarded.1. what is the significance of the battle of somme? 2. how many years into the war did it take for germany to use poison gas on a large-scale?

Who gave one of the earliest accounts of the topography and tribes of the great plains?

How did the completion of the transcontinental railroad change the lives of american citizens? a-it increased the wealth of all americans and enabled them to travel more.b-it made cross-country travel too expensive for ordinary americans.c-it decreased the safety of americans who moved to settle the plains.d-it shortened travel time between the east and west for all americans.