这种植物是慢生长的，需要几年才能完全成熟。

This plant is ___slow-growing and takes several years to fully mature.

这种松树生长缓慢，需要超过50年才能完全成熟。

This type of pine tree is ___slow-growing, taking over 50 years to fully mature.

退休基金通常包含一些回报缓慢但风险较低的投资。

Retirement funds often include some ___slow-growing but low-risk investments.