Like other amphibians, the wood frog (Rana sylvatica) is unable to generate its own heat, so during periods of subfreezing temperatures,_____ it by producing large amounts of glucose, a sugar that helps prevent damaging ice from forming inside its cells. Which choice completes the text so that it conforms to the conventions of Standard English?
A. had survived
B. survived
C. would survive
D. survives
The correct answer and explanation is:
The correct answer is B. survived.
In this sentence, the correct verb tense must agree with the structure of the rest of the sentence. The phrase “during periods of subfreezing temperatures” indicates a past action or condition. The sentence is describing a general fact about the wood frog’s ability to survive freezing temperatures, which is a habitual or regular occurrence.
The main clause “_____ it by producing large amounts of glucose” describes how the frog manages to survive the cold, making this a general statement of fact. For such general truths, the simple past tense “survived” is appropriate because it implies that the wood frog consistently survives these conditions in the past and continues to do so, rather than implying a hypothetical or future event.
Let’s break down the other options:
- A. had survived: The past perfect tense is used to indicate an action that occurred before another action in the past. Since there is no second past action in the sentence to indicate this kind of relationship, the past perfect tense is incorrect.
- C. would survive: This modal verb form suggests a conditional or hypothetical situation, implying that the frog might survive depending on certain conditions. This is not appropriate in the context of the sentence, which is describing a regular fact about the frog’s survival strategy.
- D. survives: While the present tense may seem like a potential option, it does not fit as well as the simple past in the context of describing a past and ongoing survival trait. The sentence is referencing an event that typically occurs in the past, making “survived” the best choice.
Thus, the simple past “survived” effectively conveys that the wood frog regularly survives the cold temperatures by producing glucose.