robust

a.有活力的；健康的

roadworthy, roam, roamer, roan, roar, roaring, roast, roaster, roasting, rob, rob sb. of sth., robber, robbery, robe, robin, Robinson Crusoe, robot, robot-arm, robotic, robotics, robustly, robustness, rock, rock and roll (also ,rock 'n' `roll), rock salmon, rock'n'roll, rock-bottom, rock-cake, rock-climbing, rock-crystal, rock-garden, rock-plant, rock-salt, rock-steady, rocker, rockery, rocket, rocketry, rockiness, rocking-chair (also rocker),