because they help trap oxygen from the atmosphere in the water for animals to breathe, ______ are important to sea life.
What are your choices?
i don't have any choices
Since this is not my area of expertise, I searched Google under the key words "trap oxygen in sea" to get this:
http://www.google.com/search?client=safari&rls=en&q=trap+oxygen+in+sea&ie=UTF-8&oe=UTF-8
In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search. Also see http://hanlib.sou.edu/searchtools/.
The missing word to complete the sentence seems to be "phytoplankton."
Phytoplankton are microscopic floating plants that play a crucial role in marine ecosystems. They are primary producers, which means they convert sunlight, carbon dioxide, and nutrients into organic matter through the process of photosynthesis. Phytoplankton serve as the foundation of the marine food chain, providing food and oxygen for a wide range of marine organisms.
To get answers like this, you can use search engines like Google. Simply type in the question or keywords related to the topic you are interested in, and browse through the search results to find reliable and accurate information. In this case, entering "why are phytoplankton important to sea life" would provide you with several informative sources to learn more about the topic.