<span id="docs-internal-guid-953a6350-7fff-cc84-abe3-117238b54c0e"><p dir="ltr" style="line-height:1.2;margin-top:0pt;margin-bottom:0pt;"><span style="font-size: 14pt; font-family: "Times New Roman", serif; color: rgb(0, 0, 0); font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; font-variant-position: normal; white-space-collapse: preserve;"> The question is a complex sentence. Preceded by an adverb clause that starts from the blank and continues to the word “trip” before the comma, the main clause is “feel free to contact Ms. Smith.” Following this logic, we can eliminate Choice (B) </span><span style="font-size: 14pt; font-family: "Times New Roman", serif; color: rgb(0, 0, 0); font-style: italic; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; font-variant-position: normal; white-space-collapse: preserve;">Did</span><span style="font-size: 14pt; font-family: "Times New Roman", serif; color: rgb(0, 0, 0); font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; font-variant-position: normal; white-space-collapse: preserve;"> and Choice (C) </span><span style="font-size: 14pt; font-family: "Times New Roman", serif; color: rgb(0, 0, 0); font-style: italic; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; font-variant-position: normal; white-space-collapse: preserve;">Had</span><span style="font-size: 14pt; font-family: "Times New Roman", serif; color: rgb(0, 0, 0); font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; font-variant-position: normal; white-space-collapse: preserve;"> first because if they are used, the whole question should end with a question mark, and there would be no comma to separate it. </span></p><br><p dir="ltr" style="line-height:1.2;margin-top:0pt;margin-bottom:0pt;"><span style="font-size: 14pt; font-family: "Times New Roman", serif; color: rgb(0, 0, 0); font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; font-variant-position: normal; white-space-collapse: preserve;">Next, let’s focus on the adverb clause, “______ you have any questions regarding the details of the upcoming company trip.” The blank should be filled with a subordinating conjunction that starts an adverb clause.</span></p><br><p dir="ltr" style="line-height:1.2;margin-top:0pt;margin-bottom:0pt;"><span style="font-size: 14pt; font-family: "Times New Roman", serif; color: rgb(0, 0, 0); font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; font-variant-position: normal; white-space-collapse: preserve;">It’ true that Choice (A) </span><span style="font-size: 14pt; font-family: "Times New Roman", serif; color: rgb(0, 0, 0); font-style: italic; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; font-variant-position: normal; white-space-collapse: preserve;">However</span><span style="font-size: 14pt; font-family: "Times New Roman", serif; color: rgb(0, 0, 0); font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; font-variant-position: normal; white-space-collapse: preserve;"> can be used as a subordinating conjunction to start an adverb clause, but it means “No matter how,”and the meaning doesn’t fix the context. Only Choice (D) </span><span style="font-size: 14pt; font-family: "Times New Roman", serif; color: rgb(0, 0, 0); font-style: italic; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; font-variant-position: normal; white-space-collapse: preserve;">Should</span><span style="font-size: 14pt; font-family: "Times New Roman", serif; color: rgb(0, 0, 0); font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; font-variant-position: normal; white-space-collapse: preserve;"> is the correct answer. </span></p><br><p dir="ltr" style="line-height:1.2;margin-top:0pt;margin-bottom:0pt;"><span style="font-size: 14pt; font-family: "Times New Roman", serif; color: rgb(0, 0, 0); font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; font-variant-position: normal; white-space-collapse: preserve;">When Choice (D) </span><span style="font-size: 14pt; font-family: "Times New Roman", serif; color: rgb(0, 0, 0); font-style: italic; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; font-variant-position: normal; white-space-collapse: preserve;">Should</span><span style="font-size: 14pt; font-family: "Times New Roman", serif; color: rgb(0, 0, 0); font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; font-variant-position: normal; white-space-collapse: preserve;"> is filled into the blank, the whole question is a conditional sentence to express what might happen in the future but indicates a little more uncertainty or doubt than a first conditional sentence. A conditional sentence pattern with “should” is as follows:</span></p><br><div dir="ltr" style="margin-left:0pt;" align="left"><table style="border-width: initial; border-style: none; border-color: initial; table-layout: fixed; width: 468pt;"><colgroup><col></colgroup><tbody><tr style="height:0pt"><td style="border-width: 1pt; border-left-style: solid; border-color: rgb(0, 0, 0); border-bottom-style: solid; border-top-style: solid; vertical-align: top; padding: 5pt; overflow: hidden; overflow-wrap: break-word;"><ul style="margin-top:0;margin-bottom:0;padding-inline-start:48px;"><li dir="ltr" style="list-style-type: disc; font-size: 14pt; font-family: "Times New Roman", serif; background-color: transparent; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; font-variant-position: normal; white-space: pre;" aria-level="1"><p dir="ltr" style="line-height:1.2;margin-top:0pt;margin-bottom:0pt;" role="presentation"><span style="font-size: 14pt; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; font-variant-position: normal; text-wrap: wrap;">If + S1 + should + the basic form of a verb, S2 + would/ could/ should/ might + the basic form of a verb. </span></p></li><li dir="ltr" style="list-style-type: disc; font-size: 14pt; font-family: "Times New Roman", serif; background-color: transparent; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; font-variant-position: normal; white-space: pre;" aria-level="1"><p dir="ltr" style="line-height:1.2;margin-top:0pt;margin-bottom:0pt;" role="presentation"><span style="font-size: 14pt; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; font-variant-position: normal; text-wrap: wrap;">If + S1 + should + the basic form of a verb, an imperative sentence</span></p></li></ul></td></tr></tbody></table></div><br><p dir="ltr" style="line-height:1.2;margin-top:0pt;margin-bottom:0pt;"><span style="font-size: 14pt; font-family: "Times New Roman", serif; color: rgb(0, 0, 0); font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; font-variant-position: normal; white-space-collapse: preserve;">In this sentence pattern, the auxiliary verb “should” can be placed at the beginning of the if-clause, but the if-clause has to be inverted. This explains why the adverb clause in the question becomes “Should </span><span style="font-size: 14pt; font-family: "Times New Roman", serif; color: rgb(0, 0, 0); background-color: transparent; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; font-variant-position: normal; white-space-collapse: preserve;">you have any questions regarding the details of the upcoming company trip.” </span></p><div><span style="font-size: 14pt; font-family: "Times New Roman", serif; color: rgb(0, 0, 0); background-color: transparent; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; font-variant-position: normal; white-space-collapse: preserve;"><br></span></div></span>