Sentence:  Consider a <WSD>shear</WSD> field with a height of H and a cross-sectional area of A opposed by a manometer with a height of h ( referred to the same base as H ) and a cross-sectional area of a . 
Meaning of the word marked with <WSD> tags:  (physics) a deformation of an object in which parallel planes remain parallel but are shifted in a direction parallel to themselves