The following answers use correct punctuation: (a) Dear Ms. Collin: When the error message appears on the screen, you should exit the program, right. (b) When you leave at 5:00 p.m., please shut the door and lock it; however, do not set the alarm.
In sentence (c) the punctuation in 1980's is not correct. It is a common mistake to include apostrophes when pluralizing a number or an abbreviation. Apostrophes are generally used in contractions and to indicate the possessive case.
The correct answer is D. Elion and her colleagues were responsible for developing important drugs.
Explanation
The statement that best summarizes the main idea of the extract is D. "Elion and his colleagues were responsible for the development of important drugs." This can be affirmed because in the extract the author says that "Elion joined the Burroughs Wellcome Laboratories" clarifying that Elion began working in laboratories where medicines were manufactured. Later, the author refers that "Elion and Hitchings developed a variety of new drugs that were effective against leukemia, autoimmune disorders, urinary tract infections, gout, malaria, and viral herpes," in this part of the Extract is where it is directly mentioned what Elión and Hitchings did when they worked in the laboratory. Additionally, some of the diseases that were cured with the medicines they had developed such as leukemia, gout, malaria, among others, are mentioned.
Answer:
Because they were born in the United States, Dred Scott and his family were citizens and had all the rights granted by the Constitution.
Explanation: