plankton

n [U] any of the (mainly microscopic) forms of plant and animal life that drift in or float on the water of seas, rivers, lakes, etc 浮游生物.

plainsman, plaint, plaintiff, plaintive, plaintively, plaintiveness, plait, plan, plane, plane geometry, plane sailing, plane-table, planet, planetarium, planetary, plangency, plangent, plangently, plank, planking, planned, planning, plant, plantain, plantation, planter, plaque, plasma, plaster, plaster cast, plasterboard, plastered, plasterer, plastic, plastic bomb, plastic explosive, plastic surgery, plasticine (also Plasticine), plasticity, plastics,