What new invention to increase the economic output of both steel and gasoline

answer; first blank(1); 30% two(2); salmonella; i believe this is correct; //good luck;

hello

question:

when would a new household be started?

a.when the oldest male died

b.when a man and a woman married

c.when the house could not hold everyone

d.when a child was born

answer: us d when a child was born

hope this have a great day and brainlest