What is the appropriate word for the blank: The report needs to be _____ by the end of the week.

The correct word for the blank in the sentence "The report needs to be _____ by the end of the week" is "completed." This choice is suitable because the sentence structure requires a past participle to follow the verb "needs to be," which indicates that an action is required to be finished by a specific time.

Using "completed" correctly conveys that the report should reach a finished state by the end of the week, aligning with the passive construction of the sentence. The phrase "needs to be" also implies that the action is necessary, and the use of "completed" maintains this meaning effectively.

In contrast, "completing" is a present participle that would not fit the sentence's grammatical structure, while "complete" is an adjective and does not express the required action. "Completes," being a simple present form of the verb, also does not work in this passive construction, which again emphasizes the necessity of having the report finished by the specified deadline.