Which of the following is a complex sentence

"Who wants to know?" Based on its purpose, what type of sentence is this?

Choose the correct word order:

A sentence that ends in a question mark is most likely:

"My boyfriend ____ attacked by a group of hooligans."

Which type of clause can stand by itself?

Which sentence contains an error of pronoun-antecedent agreement?

"He loved the gift that his mother sent us, but I abhorred it." Based on its structure, what type of sentence is this?

"He had no comment concerning the scandal." What part of speech is "concerning"?

"Which shoes did she wear yesterday?" What part of speech is "Which"?

"While I was at work, Jack cleaned the bathroom." Based on its structure, what type of sentence is this?