<p>The words/phrases in brackets are MY answers; the book answers are included afterward. Please provide an explanation for these errors. Since these sentences are not in context, I just want to know if they are grammatical as is. Sometimes, however, I think the book, Mcgraw-Hill, might be wrong. </p>
<p>test 10
19) In fact, Giant Pandas [ are by nature ] extremely solitary animals, usually avoiding direct contact with other animals. </p>
<p>ans: [ ,are by nature, ]</p>
<p>20) In [their dense] habitat, the black and white coat of the Giant Pandas may help make them more conspicuous to each other. </p>
<p>I think this is wrong because "in their dense habitat" modifies "the black and white coat." But I'm not sure because the first phrase is a prepositional phrase so maybe this sentence is genuine.</p>
<p>47) A new subdivision of homes [ building on ] a once thickly wooded plot of land often devastates the natural beauty of the area.</p>
<p>[ built on ], i know built on works, but does building on work as well?</p>
<p>50) Many builders take great care to maintain as much of the natural landscape as possible by keeping mature trees untouched [whenever possible ].</p>
<p>[omit], the reason the book provides is that "whenever possible" is redundant because "as possible" is there. what?</p>