3 Problems on Writing Practice I'm Confused from

<p>Many of the instruments used in early operations of the US Army Signal [Corps were adaptations of equipment used by the Plains Indians, particularly that of the heliograph].</p>

<p>Correct Answer: Corps, and in particular the heliograph were adpatations of quipment used by the Plains Indians.</p>

<p>My Answer: No Error</p>

<p>Is it because putting heliograph at the end makes it possibly describe heliograph as a type of Indian, or is there another reason? </p>

<p>Ms. Jordan proudly demonstrated her company's most popular product, a watch that flashes the time in lighted numerals when PRESSING A BUTTON. (capitalized is the error) </p>

<p>I got this correct but I need a concrete reason why this is an error.</p>

<p>here "when" is connected to "a watch". so pressing a button, if expanded to its full form, will be "when a watch is pressing a button".</p>