Engine 2014: Motor Plants and Auxiliary Boilers

1. A "A" to travel in a direction opposite to "B"
2. B "A" to drive "B" in the indicated direction of rotation
3. C "B" to drive "A" at any speed of "A" or "B"
4. D "B" to drive "A" when "B" provides the power for rotation

Tip: press A-D to answer