When comparing three or more things you must use the superlative construction of the adjective or adverb in question. In this case, an incorrect version of the superlative form was used. The superlative form of "stressful" is "most stressful" which is the best option to replace the underlined portion of the sentence above.

When you are comparing only two things, you must use the comparative construction of the adjective or adverb in question. When you are comparing three or more things, you must use the superlative construction instead. The best way to correct the underlined portion above is: "the swiftest in the race?"

When you are comparing only two things, you must use the comparative construction of the adjective or adverb in question. When you are comparing three or more things, you must use the superlative construction instead. The best way to correct the underlined portion above is: "I would have to choose Jeffrey because he is more beautiful than William."

When you are comparing only two things, you must use the comparative construction of the adjective or adverb in question. When you are comparing three or more things, you must use the superlative construction instead. The best way to correct the underlined portion above is: "Do you think the party will be more fun with or without firecrackers?"

When you are comparing only two things, you must use the comparative construction of the adjective or adverb in question. When you are comparing three or more things, you must use the superlative construction instead. The best way to correct the underlined portion above is: "the biggest in the whole world?"

When you are comparing only two things, you must use the comparative construction of the adjective or adverb in question. When you are comparing three or more things, you must use the superlative construction instead. The best way to correct the underlined portion above is: "but Myrtle is by far the kindest."

When you are comparing only two things, you must use the comparative construction of the adjective or adverb in question. When you are comparing three or more things, you must use the superlative construction instead. The best way to correct the underlined portion above is: "but Paula works harder."

When you are comparing only two things, you must use the comparative construction of the adjective or adverb in question. When you are comparing three or more things, you must use the superlative construction instead. In the example sentence, we are specifically told that there are "seventeen students" in the class, so the superlative is required to distinguish her from that group. The best way to correct the underlined portion above is, "Marina is clearly the best."

When you are comparing only two things, you must use the comparative construction of the adjective or adverb in question. When you are comparing three or more things, you must use the superlative construction instead. Since the example sentence only gives "student" and "teacher" as options the comparative construction must be used in this case. The best way to correct the underlined portion above is: "It's hard to know whether it is more difficult to be a teacher,"

When you are comparing only two things, you must use the comparative construction of the adjective or adverb in question. When you are comparing three or more things, you must use the superlative construction instead. Since there are usually at least three "members of [a] band," and musical partnerships are referred to as duos rather than band's, it is correct to use the superlative construction in this instance. The best way to correct the underlined portion above is: "Johnny is the most charismatic member of the band;"

Note that a semicolon correctly separates these two independent clauses.