Choose the correct form of the passive voice. 4. Two new engineers _______ just _______ to the head of the department.

The correct answer is: have been introduced.

Explanation:

The passive voice is formed using a form of the verb "to be" + past participle. In this sentence, we need the present perfect passive, because of the word "just", which indicates a recent action. Since "two new engineers" is plural, we use "have been" instead of "has been".

Therefore, the complete sentence is: Two new engineers have just been introduced to the head of the department.