Some good words

second wind
the second of
second-guess
second glance
within seconds
split second
second most successful
the Second World War
secondary modern
second class
second the proposal
second sight
second-string
secondary action
second look
per second
absolute secrecy
secondhand
secondary bonds
second language
second year
second time
second the motion
second person
second name
second
second lien
secondary data
seconded
shrouded in secrecy
second-rate
second chance
second opinion
secrecy
in a matter of seconds
second term in office
Second Gulf War
Just a second
secondly
seconder
secondary stress
secondary school
secondary industry
secondary boycott
second best
second to
second thoughts
second largest
secondhand shop
seconded to
secondary market
on second thoughts
second nature
second childhood
every second person
second-hand reports
second quarter
second-hand cloth
secondary consideration
second only to
second half
second home
secondary to
second-largest
second period
in the second
secrecies
secondary shares
secondhand store
without a second thought
second the amendment
second screen
came second
second place
second base
second-degree
Second Life
second hand
veil of secrecy
come second
every second
secondarily
seconding
rank second
second mortgage
second prize
secondary importance
second lieutenant
finish second
seconders
any second
second to none
second section
secondary
second-generation
secondary source
every second year
second-tier
secondaries
seconds

This site is full of exercises for second (2nd) grade students. These exercises are online and interactive. 2nd grade math exercises
You can learn English words in context: use in a sentence and in a sentence