C, a mystery because the sea holds many unknowns
Try and put in Key details on your speech and why the vaccine helps as well as some components how the vaccine helps the immune system
Answer:
It's is a contraction and should be used where a sentence would normally read "it is." The apostrophe indicates that part of a word has been removed. Its with no apostrophe, on the other hand, is the possessive word, like "his" and "her," for nouns without gender.