Adependent clause a. is a sentence c. is often combined with a question b. cannot be a sentence d. none of these

A dependent clause is a clause that provides a sentence element with additional information, but which cannot stand as a sentence. A dependent clause can either modify an adjacent clause or serve as a component of an independent clause.

martians or other types of aliens represent a unique fear as opposed to zombies. vampires and other types of monsters.   in most sci-fi stories, aliens come from other worlds and have different or more advanced technology.   abductions and experimentation on human bodies that involve these technologies, or the use of these technologies against human beings and the use of unknown "powers", are a type of fear that's different from that of other types of monsters.