Which country did their boss visit first

A．the capacity to generate electricity is the distinctive characteristic of the fish
B．the current travels in an upward direction from the positive side to negative side in torpedo’s electric cells
C．some fish can produce enough electricity to drive a number of electricmotors
D．the torpedo’s electric cells have a shape with six sides

A．Because they have a driving license.
B．Because they have received special training.
C．Because the traffic conditions in London are good.
D．Because the traffic system of the city is not very complex.