They have to drill farther down, to make sure of getting deep enough into the good clean water underground. And then they have to put in the pipes, and make a foundation with the gravel, and then install the pump and pour cement around it.
Compare with "comprehend" in this list. The verbs can be synonymous, but while "grasp" can also refer to physically holding something (compare with "cling" in the list for Chapters 4-8), "comprehend" connects only to intellectually catching hold of meanings.
It was all a blur to Salva, for he was too excited to sleep, which made him too tired to grasp everything that was happening.
Compare the description of the plane here to the one in the example sentence for "veer" in the list for Chapters 1-3. A bird is also mentioned here--not in a simile but in a contrast. Not only is the plane unlike a bird, but it also seems more like a person. This personification, with the lumbering and trying hard, makes the readers want to root for the plane, as they would for Salva (whom the plane seems to symbolize).
Somehow it did—not like a bird lifting off lightly with a quick flapping of wings, but with shrieks and roars from the engines as the plane lumbered down the long runway, as if it had to try as hard as it could to get into the air.
so remarkably different or sudden as to cause momentary shock or alarm
Compare with "amazed" in this list--both connect to shock, but as the Old English root ("steartlian" means "to kick") and this example sentence suggest, "startling" often includes a physical reaction while "amazed" is only emotional.
Salva’s first taste had been startling—all those bubbles jumping around in his mouth!
Compare with "grasp" in this list. The Latin "prehendere" means "to grasp" and can be seen in the adjective "prehensile" which could describe a monkey's tail that's wrapped around a tree; it can also be seen in the verb "apprehend" which (similar to "grasp" but unlike "comprehend") has both the physical and intellectual sense of catching hold of someone or some idea.
His eyes read the words, but at first his brain could not comprehend them.
the feeling that accompanies something extremely surprising
Compare this noun to the adjective "amazed" in this list. In the same part of speech, the words would be synonymous, although their roots would make "astonish" a stronger verb: the Latin "tonare" means "to thunder" while the Middle English "masen" means "to confuse" (this once connected "amaze" to "maze" and "bewilder" but this meaning is no longer used).
"Persevere" and "persist" can be synonyms, but their difference is seen in their Latin roots: "severus" means "severe" so to persevere is to continue despite harsh conditions, which gives the verb a positive and admirable tone; "sistere" means "to stand" so to persist is to continue doing or being, regardless of obstacles or warnings, which can make the verb synonymous with being stubborn, repetitive, or annoying.
I overcame all the difficult situations of my past because of the hope and perseverance that I had.
The Latin "pro" means "forward" and "facere" means "to make"--in this simplest sense of making something that results in a forward movement, Salva's organization is profitable for the Dinka and Nuer communities of Sudan. But in the sense of making money for itself, Salva's organization is nonprofit.
As of June 2010, Salva Dut’s nonprofit organization, Water for Sudan, had drilled dozens of wells in southern Sudan for Dinka and Nuer communities.