gradual

向可再生能源的过渡是一个渐进的过程。

The transition to renewable energy is a ___gradual process.

本世纪海平面逐渐上升。

There was a ___gradual rise in sea levels over the century.

我们观察到她的语言技能逐渐提高。

We observed a ___gradual improvement in her language skills.