Question

genealogy is the study of family origins and history. genealogists ______ lists of ancestors, which they arrange in pedigree charts or other written forms.
(a) compile
(b) compiles
(c) compiling
(d) have compiled
20 genetic genealogy creates family history profiles, biological relationships ______ dna test results in combination with traditional genealogical methods. by using genealogical dna testing, genetic genealogy can determine the levels and types of biological relationships between or among individuals.
(a) between, or among individuals by using
(b) between or among, individuals by using
(c) between or among individuals, by using
(d) between or among individuals by, using
21 this branch of genetics became popular in recent years, as costs ______ drastically reduced and genealogical studies using molecular techniques became accessible to the general public.
(a) are
(b) is
(c) was
(d) were
luis felipe guerra is intrepid deputy operations manager in guatemala, but he is also maya, and a tour guide. as a child, he struggled to come to terms with his indigenous heritage. 22 ______ by discovering more about his history, and sharing it with travelers, he has learned to take pride in it. now he wants to help young guatemalans do the same.
(a) essentially,
(b) nevertheless,
(c) previously,
(d) therefore,
23 in high school, ______ geared towards careers in tourism. luis learned about the equinox and how the maya planned their agriculture by following astronomical events, by learning the rhythm of the seasons. he found a passion to share the history of his people, to share thousands of years of civilization with anyone that wants to know about it.
(a) students lessons were
(b) student’s lessons were
(c) students’ lessons were
(d) students’s lessons were

Explanation:

• Question 19: The sentence is in the present tense and the subject "genealogists" is plural. "Compile" is the correct verb form for a plural subject.
• Question 20: "By using" is the correct prepositional phrase to show the method.
• Question 21: The sentence is in the past tense and the subject "costs" is plural. "Were" is the correct verb form for a plural subject in the past tense.
• Question 22: "Therefore" shows a cause - effect relationship. Luis struggled with his heritage but then learned to take pride in it (by discovering and sharing), so "Therefore" is appropriate.
• Question 23: "Students'" is the correct possessive form for plural students.

Answer:

1. A. compile
2. A. between, or among individuals by using
3. D. were
4. D. Therefore,
5. C. students’ lessons were