To Develop
する verb
Let's depart from this place and expand it out. To do that we'll have to develop it.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well. The はつ gets shortened to はっ, though.
百年前と比べて、日本は大きく発展した。
Japan has developed considerably compared to 100 years ago.
この国が発展するかどうかは、若者にかかっています。
Whether this country will develop or not depends on the youth.
年寄りの風邪は肺炎に発展しやすいんだよ。
When old people catch a cold, it can easily develop into pneumonia.