Answer:
<u>stonewort, and many green algae such as the Spirogyra.</u>
Explanation:
- As it was believed that the land algae were believed to be evolved from the stonewort plant and the blue-green algae like the cyanobacteria and the spirogyra that colonized the lands some 500 mn years ago was a freshwater alga.
- After which the first land plants occur about 470 million years ago, and they were in the form s of moss and liverworts of the vascular in origin.
The more the people, the more pollutant they generate which will pollute the the water.
23. The answer would be the third option.
24. The answer would be the second option.