Irreversible Word Pairs

Phrase in or to the forefront of activity or consideration
At the Maker Faire, an event that has built a following by showcasing the tinkering of inventors, children were front and center at every booth, touching, playing and asking exhibitors how their inventions work.
Adverb with never-ending effort
Kids these days are spoiled rotten. They have no social skills. They’re attended to hand and foot by adults so protective that if the child as much as stumbles, the whole family will curse the ground.
Adverb at a tremendous rate
Most 'successful' travel bloggers don't make money hand over fist. Budgets are tight, but because tourism agencies and other sponsors foot the bill, thousands of writers and photographers are free to travel the world.
Phrase in a difficult position, esp. without resources
high and dry
These days employees are expected to be available around the clock. If you take time off or don't work long hours you're seen as uncommitted, and can get left high and dry when bonus time comes around.
Phrase everywhere
high and low
We are surrounded by vastness, high and low. The number of stars in the heavens is unbelievably large, but there are just as many molecules of H2O in just 10 drops of water!
Phrase speaking imprecisely; to a certain extent
more or less
A seven-foot evergreen will bear 350,000 needles, more or less. The Christmas tree industry is funding research to make sure that precious few end up on the floor, by cultivating a tree with perfect needle retention.
Phrase phrase used to describe a stark difference between two things
"The HealthCare.gov website is night and day from where it was on Oct. 1st. The majority of users are now able to move smoothly through the application process, and it's now easier than ever to enroll in coverage."
Phrase at some future time; eventually
sooner or later
You are most likely familiar with "The Girl From Ipanema." Get put on hold often enough, wander through enough retail stores or tacky cocktail lounges, and sooner or later its limpid strains will caress you.
Phrase trying out different ways of doing something until one finds the most successful
trial and error
Bowerbirds build some of the most detailed, aesthetically-pleasing objects of any bird. The creative process shows off each individual's own tastes and preferences, and involves a lot of trial and error and 'changes of mind.'
Phrase in various places throughout
up and down
A power outage cut electricity to millions of people up and down the American southwest, prompting some residents to bond in ethereal fire lit settings.