1. B: The semicolon is incorrect punctuation here. With the coordinating conjunction "and," no punctuation is needed between the two gerunds. A comma is permissible to indicate David did not necessarily do both things simultaneously; however, semicolons are for separating two independent clauses, or separating dependent clauses/phrases containing internal commas.
2. A: "High School" is incorrect capitalization. These words are not names/proper nouns and should not be capitalized.
3. D: The singular form of the verb ("plays") disagrees with the plural noun subject ("Nurses"), representing incorrect grammar.
4. C: "Tonsels" is an incorrect spelling of the word "tonsils."
5. C: "Serine" is an incorrect spelling of the adjective "serene," meaning peaceful (indicated by sentence context), confusing it with the noun serine, meaning the amino acid.
6. B: Ending this question with a period is incorrect punctuation. It should end with a question mark.
7. C: "Bachalor" is an incorrect spelling of "bachelor."
8. B: The comma is incorrect punctuation. No punctuation mark is needed here.
9. D: A singular predicate with a plural subject is incorrect subject-verb agreement, i.e. grammar.
10. A: The noun "dean" is not a name/proper noun, so the capitalization is incorrect.
11. C: "Fradulent" is incorrect spelling of the adjective "fraudulent."
12. B: The comma before the adverbial clause ("when...") is incorrect punctuation; it should not be there.
13. C: "Comtemporary" is an incorrect spelling of "contemporary."
14. D: The plural verb "were" with the singular noun subject "wound" lacks subject-verb agreement, constituting incorrect grammar.
15. C: "Defendint" is an incorrect spelling of the word "defendant."
16. A: The lower-case initial "t" in "Tuesday" is incorrect capitalization: names/proper nouns are capitalized.
17. B: The semicolon here is incorrect punctuation. The only punctuation mark this sentence needs is its final period.
18. D: The correct past-perfect form here is "was known." "Was know" is incorrect grammar.
19. D: "Create" is incorrect grammar here. The singular subject noun "inventor" requires either the singular verb form "creates" or the past-tense "created" for correct construction.
20. B: It is incorrect punctuation to place a comma between the noun and its modifying prepositional phrase. No punctuation mark should be used, except for the final period.