The sentence that correctly uses the word "principal" is the second sentence. The word "principal" refers to the person who has the highest authority in an institution, particularly as referred here, which is a school. On the rest of the sentences, the right word to be used is "principle" and not principal.
Answer:
Confused, worried and surprised
Answer:
A metaphor is a figurative language that compares two unlike things directly
Explanation:
My brother is a piglet
The child can not be a pig but can share pig characteristics, like playing in the mud and being untidy. The brother and the pig are being compared directly.