they occur in spring and summer time
spring and summer
The Summer Olympics occurs every four years!
Every four years.
every 4 years
in the spring and summer months
Every 4 (four) years. The next is 2016. The summer Olympics occur every 4 years.
Every four yearsThe summer Olympics occur every 4 years.
Every 4 years, alternating summer and winter.
many thunderstorms occur in spring and summer but intense thunderstorms occur around tornado season