it" refers to,,,,surgical procedures|accident victims|==a pint of whole blood|surgery patients">
1
them" in the paragraph refers to,,,,indoors|seasons|==games|areas">
2
it" in the paragraph refers to____.,,,,the economic boom|==the Second World War|the 1930s|the United States">
6
it" in bold in the paragraph refers to___________.,,,,the mantle|==the crust|the Earth|the core">
17
it" in the paragraph refers to,,,,trestle base|space|==table|chest board">
23