Locate the gerund phrase and identify its noun use. you could have understood the speech better by listening critically.

The gerund phrase is "listening carefully."it is the object of the preposistion

A. they give the reader hope. if the whole book was dark & unhopeful it’d be a little less interesting, little moments make it more interesting to read because then you want to know what happens. if it’s all dark there’s no point in reading if you already know the outcome of it.