In addition to affecting weather, jet streams can also affect the _____.
A.way water flows along Earth's surface
B.direction in which airplanes are able to fly
C.number of convection cells in Earth's atmosphere
D.time it takes an airplane to fly from one place to another
B. Jet streams are very powerful air currents, and it's very inconvenient for a plane to have to go against the direction of a current. They have to plan their flights to avoid these currents or be aided by them.
