This is considered a 'fear tactic'.
They're basically saying, "Buy our sunscreen or you'll turn out like this!"
It means that you are aware and are paying attention.
Sentence fluency refers to the ease with which words and groups of words flow when read or spoken, so the best answer is "Combining sentences to use complex structure" although that's not a great definition.
A subordinating conjunction is a conjunction that introduces a subordinate clause. For example although, because, etc. So the correct answer is because.
Hope this helps! :)
