I think it’s money sorry if I’m wrong
The column of mercury in the barometer is lowest when the barometer is ion location 4. Atmospheric pressure measured by the barometer decreases with an increase in altitude. Atmospheric pressure is caused by the column of air above the ground level at any given point on the earths surface thus an increase in altitude leads to a decrease in this column leading to a decrease in atmospheric pressure.
One is probably because your friend has a stronger immune system than you and is able t fight the bacteria infection. The other is probably that your friend is also infected but does not show any symptoms of the infection, in what is referred to as latent infection. The bacteria enters a lysogenic cycle in your friend’s body rather than the more virulent lytic cycle (that happens to you).