immature wood

例句：

1. 1.The tree was still young and its bark was immature.
   这棵树还很年轻，它的树皮还很不成熟。
2. 2. The fruits were immature and would not ripen until later in the season.
   这些水果还不成熟，要到季节晚些时候才会成熟。
3. 3. The baby's skin was immature and needed extra care.
   婴儿的皮肤还很不成熟，需要额外的照顾。