The answer to your question would be that the verb that should be used with the helping verb "had" in the sentence is the following one: frozen. That is, the sentence would be as follows "despite the grove owners' hard work, the orange crop had frozen overnight.
The auxiliary verb "have" in the past indicates that the following verb should be in the past participle form for the sentence to be in the past perfect tense. The past participle of the verb "to freeze" is "frozen".
b. Controlled experiments cannot be conducted on living things.
c. A controlled experiment only tests one variable at a time.
d. Scientists always utilize controlled experiments.
Answer:
Fragment
Explanation:
This phrase is a fragment because it lacks a subject, which is one of the most important requirements of a sentence. Without a subject, we have no way of knowing who is performing the action described by the verb. Therefore, in order to turn this fragment into a sentence we would need to add a subject, such as "I," "he/she," "we" or "they."