Based on the information in figure 2 which substances would be gas is at 0°c

As we can see from the table that boiling point of Nitrogen and Hydrogen is -195.8 and -252.9 degree Celsius.

So at 0 degree Celsius both of the gas will reach to the boiling point and will convert into the gaseous state

while other two substance will remain in liquid state or solid state at 0 degree C because they both have greater boiling temperature or boiling temperature greater than zero.

So the answer would be

Nitrogen

Hydrogen

i am pretty sure it is c because when people are closer together, they cannot move as freely. picture being in a mostly full elevator, for instance. the people are right next to you, and you can barely move.

d) physical means can be used to separate the components of air.