Answer:
Cranial and facial bones compose the skull.
The upper extremity is connected with the trunk by the shoulder.
Each gland produces secretions.
The spinal column is formed by the vertebrae.
Explanation:
In grammar, the term <em>voice</em> refers to the relationship between the action or state expressed by the verb and the participants of the sentence, such as the subject, object, and others. There are two voices in English:
- The active voice - the sentence has a subject that acts upon its verb (e.g <em>Jake is writing a book</em>).
- The passive voice - the subject is the recipient of a verb's action (e.g. <em>A book is being written by Jake</em>).
In the given question, we need to pay attention to the context and the way the sentence is constructed. We can recognize sentences where passive voice will be used by the construction<em> by + the word marking who performs an action</em>. This is why the passive voice will be used in the second and fourth sentences, and active voice in the first and the third sentences.
