1.The _____ live next door.

A) Smith's
B) Smiths
I answered B
2.Select the sentence which is correctly punctuated:
A) The diagnosis was "gastroenteritis acute."
B) The diagnosis was "gastroenteritis, acute."
C) The diagnosis was "gastroenteritis, acute".
I answered C but feel it could be B too.

The first is correct; the second one isn't.

So the quotation marks go outside of the period then?

So the quotation marks go outside of the period then? It's B

Right.

1. To determine the correct answer for the first question, you need to understand the rules of plural possessive nouns. In this case, we want to express that the neighbors belong to the Smith family. The correct answer is A) Smith's.

Explanation:
To indicate possession for singular nouns, we usually add an apostrophe and an "s" ('s) to the end of the noun (e.g., "the cat's toy"). However, when dealing with plural nouns that already end with an "s," we only need to add an apostrophe (') at the end to indicate possession. Therefore, the correct form of the plural possessive noun for "Smith" is "Smith's" (without an additional "s").

2. To determine the correct answer for the second question, you need to consider the rules for punctuating quotations.

Explanation:
When punctuating a quotation within a sentence, we typically use quotation marks to indicate the beginning and end of the quotation. We also need to place any necessary punctuation marks within the quotation marks. In this case, the correct answer is B) "The diagnosis was 'gastroenteritis, acute.'"

The comma after "gastroenteritis" is necessary for correct punctuation. However, we don't need another comma following the closing quotation mark, as this punctuation would be redundant. Therefore, the correctly punctuated sentence is: "The diagnosis was 'gastroenteritis, acute.'"