Question 24:
When the COVID-19 virus (24) ______ someone, most of them will get a mild to moderate respiratory illness and get better on their own.
Answer: B. infects

• The correct word here is "infects," as it refers to the virus causing an infection in someone.

Question 25:
Chronic diseases like heart disease, diabetes, lung disease, and cancer are more likely to happen to older people (25) ______ already have health problems.
Answer: C. that

• "That" is used to refer to people or things in restrictive clauses. It connects the clause about people who already have health problems.

Question 26:
Keep yourself and (26) ______ hands often with an alcohol-based rub.
Answer: B. the other

• "The other" refers to someone else (another person). This makes sense in the context of advising individuals to wash their hands.

Question 27:
At this point, there are no (27) ______ medicines or vaccines that can protect against COVID-19.
Answer: B. specific

• "Specific" refers to particular medicines or vaccines designed for COVID-19.

Question 28:
(28) ______ there are a lot of clinical trials going on right now that are looking at possible treatments.
Answer: C. But

• "But" indicates a contrast or exception to the previous statement, emphasizing that although no specific treatments exist yet, trials are ongoing.