Question

usually live in water either floating or attached to the bottom​

Answer 1

Answer:

ceolentrates

Explanation:

ceolentrates usually live in water .ex Hydra,polyp

Answer 2

ANSWER:

The aquatic plant are best example for floating or attached plant to bottom.

EXPLANATION:

The aquatic vascular plant have originated in this fashion. They survive in  saline, brackish and salt water. The sea grasses are only example that are capable of 'growing completely submerged' in sea water.

The thalassia and zostera are other example for plant growth. They act as oxygen source to the fish and also provide the food to the fish and other marine organism.