Identify unnecessary verbs in the following sentences describing the measurement of poly(methacrylic acid) (PMMA) elasticity with an Atomic Force Microscope (AFM).[1]
An AFM was used to measure the entropic elasticity due to the uncoiling of individual polymer chains of PMMA.
We performed AFM measurements to evaluate the entropic elasticity due to the uncoiling of individual polymer chains PMMA.
The measurement of the entropic elasticity due to the uncoiling of individual polymer chains of PMMA was done with an AFM.
The entropic elasticity due to the uncoiling of individual polymer chains of PMMA were made with an AFM.
We tried an AFM to measure the entropic elasticity due to the uncoiling of individual polymer chains.