What consists of three stages

Efficiency is the percent of work put into a machine by the user (input work) that becomes work done by the machine (output work)

Pentane with molecular formula c5h12, exists in three isomeric forms. one shows linear carbon chains, another has one -ch3 groups present on the third carbon atom, and the third has two -ch3 groups present on the second carbon atom. what types of isomers are these? a. geometric isomers b. structural isomers c. halotropic isomers

Who discovered tuberculosis bacteria?