Question

these plant produce 90/: of the earth.
(a).Algae
(b).plankton
(c).sea weeds
(d).water hyacinth​

Answer 1

Answer:

3.4.6 Aquatic Weeds

The difficulty of controlling aquatic weeds is related to their habitat not their life cycle. Seventy percent of the earth's surface is covered with an interconnected water system. Ultimately, all water flows to the sea and all contaminants can be carried along as dissolved solutes or adsorbed to eroded soil. Almost all water contamination is, in the minds of most people, unacceptable. Because of heightened and enlightened concern about environmental quality, the unacceptability of contaminating water has resulted in legislation to prevent, control, and, if necessary, punish water pollution. Only a few herbicides can be used in aquatic systems. Present and future herbicides must be compatible with all other actual and potential uses for water. This is a very difficult requirement, and extensive, expensive research will be required if acceptable weed control with herbicides is to be developed. In the aquatic environment, it is likely that proof of safety will be demanded by an anxious public. Reasonable assurance or reasonable doubt will not suffice. It is equally true that expensive research will be required if nonchemical techniques for aquatic weed management are to be developed. Because of these appropriate concerns, the aquatic environment is a likely site for development of nonchemical-control techniques.

Explanation:

Mark as brainlist please @ Thor 9858