1. You blow up a party balloon and tie it. Compared to the gas pressure on the outside of the balloon, the gas pressure on the inside is
A. the same    B. lower    C. higher    D. indeterminate    E. zero


2. The best explanation for why a vaccuum cleaner works is
A. brushes beat the dirt and air on the outside into the bag
B. the negative air pressure inside in the bag sucks dirt and air from outside into the bag
C. the higher atmospheric pressure on the outside causes outside air to flow toward a region of lower gas pressure in the bag carrying dirt along with it
D. ?