Vocabulary consisting only from characters you are able to read
億
oku
(num) 100,000,000, hundred millionjlpt4
野山
nojama
hills and fields, hill and dalemix
何度か
nandoka
several times, one or twicemix
開花
kaika
(1)flowers budding, blooming, flowering, (2)showing results, becoming popular, blooming suru