When you are finished, you should be able to: 1  State the role of a helping verb and list some examples. 2  Explain how helping verbs can clarify the verb tense of a sentence. 3  Identify helping verbs in a sentence.
The dry cell battery is one of the most commonly used types, including AA, 9-volt, and watch batteries. Dry cell batteries are different from wet cells because their electrolytes are contained in a low-moisture paste, while a wet cell has electrolytes contained in a liquid, hence the difference in names.
Alkaline batteries (IEC code: L) are a type of primary battery dependent upon the reaction between zinc and manganese dioxide (Zn/MnO2). Another type of alkaline batteries are secondary rechargeable alkaline battery, which allows reuse of specially designed cells. Compared with zinc-carbon batteries of the LeclanchÃ© or zinc chloride types, alkaline batteries have a higher energy density and longer shelf-life, with the same voltage.