(February 2013) Durham tubes are used in microbiology to detect production of gas by microorganisms. They are simply smaller test tubes inserted upside down in another test tube. This small tube is initially filled with the solution in which the microorganism is to be grown.
A compound predicate is two or more simple predicates joined by a conjunction that indicate actions by the same subject. Example : Bill picked up the mail and walked the dog.. Bill is the subject for both verbs.
Search. The predicate is the part of the sentence that makes a statement about the subject. The predicate usually tells us what the subject is doing or what is happening to the subject. A compound predicate tells us two (or more) things about the same subject (without repeating the subject).he predicate is the part of the sentence that makes a statement about the subject. The predicate usually tells us what the subject is doing or what is happening to the subject.