Concept:
A reversible plough is designed to turn the furrow slice in either direction. It helps in continuous ploughing without forming dead furrows and back furrows.
Step 1: In plough operation, wheel position affects balance and depth control.
Step 2: In a reversible plough, both sides of the plough must work uniformly.
Step 3: Therefore, the two furrow wheels should rest at the same height.
Step 4: Same height ensures uniform working depth and stable operation.
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\boxed{\text{Same}}
\]