Answer:
Electrically powered, hydraulic steering system
These are my favorite riddles/questions, the answer will be he will wait till nighttime and go through the first door. <span />
There would be six bands on the electrophoretic gel.
The linear strip would be cut twice by the EcoR1 and thrice by the HindII. That would be an equivalent of 5 cuts on a linear piece that would result in 6 pieces.