(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.
Compound verbs Compound verbs are two words which combine to make one meaning. The first word is usually a noun, an adjective or a preposition, and the second word is a verb. The words are sometimes written as one word and sometimes joined by hyphens. A good learnerâs dictionary will tell you how the compound is normally written: â¦