unretentive

adj.无保持(力)的 无保留(力)的

缺乏记忆力的；难遗忘的

形容词

1. She is unretentive and often forgets things soon after hearing them.
她记忆力很差，往往听完东西就忘记了。

2. The unretentive nature of the material made it difficult for students to retain the information.
这些材料的容易遗忘性使得学生难以记住这些信息。