Sentence:  <WSD>Backhoe</WSD> pits and trenches are an economical means of performing subsurface exploration. The <WSD>backhoe</WSD> can quickly excavate the trench that can then be used to observe and test the in situ soil (see Fig. 2.29). 
Meaning of the word marked with <WSD> tags:  A multi-purpose tractor with a front-mounted loading bucket and a rear-mounted digging bucket.