Tools used to measure length include a ruler, a Vernier caliper, and a micrometer screw gauge. Vernier calipers and micrometer screw gauges are more precise and can be used to measure the diameter of objects like pipe and wire.
I hope it helps
I am 60% positive that the answer is A. gust of wind but not 100% so hope you get this right :)
"The domesticated generations fell from him" means that Buck is losing his civilized characteristics (B).
In this passage, Buck is feeling more and more estranged from where he and his ancestors ("generations") originally come from: as he gets a taste of wild life, he feels less and less like a pet ("domesticated") and more like a feral dog or a wolf. He is forgetting his stay-at-home ways ("fell from him") and sees new instincts grow in him, such as the drive to fight and hunt in a pack.
The adjective is cool, it modifies holes, and it answers what kind of holes.
Hope that helps
