Speaking very technically, taking (2) to be true (A massive algae bloom starved the dolphins) does not necessarily end our search. While the dolphins may have been starved, could something else not have killed them while they were starving? An analogous situation would be one dying of a gunshot wound while they had the flu. You may very well think that the flu was the cause of their death (or caused the thing which causes their death), but we should be careful about assuming that one thing (however likely for death) guarantees their death, especially when an intervening phenomenon may break the chain of causation. This may be a pedantic point, but one I found worth mentioning.

If most implies some, for example, we know that most is the sufficient condition for some M→S". Some would be the necessary condition for most "/S → /M". we know that necessary conditions are the superset, and its sufficient condition as a subset. Although that may initially seem counterintuitive by our standards that some is included in all (all is just some combination of a bunch of "somes"), by a strictly logical definition we can determine that the greater value is indeed a subset of the lesser value, given that it must fulfill that value but there are cases where it doesn't (some dogs like bacon, but not most). Hope this helps!

Think about the validity of the claims to be determinable when we assign T/F values. The ultimate question for this problem is: is there anything that necessitates that the vote will not pass? If SAS is "true" based on the truth of other claims (say if the third sentence was AAF→SAS instead of /AAF→/SAS, then we have one circumstance where it is necessary (SAS→/P, so AAF→/P). If we have no way of knowing SAS is "true" (e.g. cannot determine through logical connection), then there is not enough info to make a conclusion one way or the other. My main point is that while it is important to consider action indicators like "can," "cannot," "will," etc, focus on how the truth value of each premise changes based on others being proven/disproven.

In terms of expression in logic, the "or" symbol is separate from the conditional "→". There are many other logical symbols yet to be introduced in this course, but these "ors" are traditionally referred to as a disjunctive, denoted by a vell "∨" as a symbol. The default assumption is usually that they are inclusive, meaning at least one or both. But either way, it can never be the case that neither options are true. So if we have the sentence "Bob or John is the robber", and then I say that "John is not the Robber" we are guaranteed that Bob is the robber, since it cannot be John (and thus cannot be both of them), and by assumption of the logical value of the "∨" it cannot be neither of them.

You are correct, it IS necessary for BO to occur if there is a Heatwave, or /HWA. But it is not necessary that HWA if there is a BO. This is because it would be false to say HWA → /BO, as we could say that a power station shut down (call it PS) and caused the blackout, and thus the BO would occur. Put succinctly, PS & HWA → BO, that is PS and HWA occur together, and still produce the same result. The question is, do the antecedents (stuff before the conditional) guarantee the consequence? I hope this makes sense!

Think about the object clause as a way of bracketing information that's further in, as they said, a "nested clause". So, such a nested clause should contain a subject and a predicate. In other words, it should be a fine stand-alone sentence. So, "it will have a significant impact on the perspectives..." would qualify. "a significant impact on the perspectives..." does not sound as sensical. It seems what you were getting at in your answer is the tendency to try and break it down further. This can certainly be done by isolating the object clause's predicate, or "will have (verb) a significant impact on the perspective of many viewers (object)". The future tense possessive (will have) is also an added confusion, but for simplicity I think of it as "has", unless the tense specifically matters.

I took it to be because we are distinguishing between regular novels and successful novels, namely that the latter type must deliver x and y. Put another way, we should be able to replace "those" with the noun, in this case "Novels". If we tried to instead put in "successful novels", we would get a redundant sentence, which does not prove anything: The most successful novels have been successful novels that deliver x and y. Although this is a possible interpretation, you can assume that questions are not formatted this way (an identity statement of a=a is not useful information and thus not worth distinguishing). To take take your second point, "not all novels deliver x and y", that is correct. But then we know that all successful novels deliver x and y (successful novel ↔ delivers x and y).