ridge-pole

n horizontal pole at the apex of the roof of a long tent （长形帐篷的）横梁.

riches, richly, richness, Richter scale, rick, rickets, rickety, rickshaw, ricochet, rid, riddance, ridden, riddle, ride, ride down, ride off, ride on, ride over, rider, ridge, ridge-tile, ridgeway, ridicule, ridiculous, ridiculously, ridiculousness, riding, riding-crop, riding-school, rife, riff, riff-raff, riffle, riffraff, rifle, rifle-range, rifleman, rifling, rift, rift valley,