untidy
加入词篮until
untrue
unusual
unusually
unveil
unvoiced
unwilling
unworkable
up
up and down
up to date
up-to-date
upbringing
upcoming
update
upfront
upgrade
upgrowth
uphold
upholster
upholstered
upholsterer
upholstery
upland
upload
upon
upper
upper class
uppers
upright
upright
uprising
uproar
upset
upset
upside
upside down
upside-down
upstairs
upstanding
uptown
upward
upwards
Uranus
urban
urbanization
urbanized
urethra
urge
urgency
urgent
urinary system
urine
urn
Urumchi
Urumqi
us
USA
usage
usage
use
use up
used
used to
useful
useless
user
usher
usual
usually
usurpation
usurper
utensil
uterus
utilise
utilitarian
utilitarianism
utility
utilization
utilize
utmost
utopia
utter
utterly
V-neck
V-necked
vacancy
vacant
vacation
vacationer
vaccinate
vaccine
vacuum
