a. 不屈曲的, 不屈挠的, 顽固的

◆记忆方法一：
词根词缀记忆法：inflexible a 不弯的，不屈的（in不+flexible→不弯曲的；不灵活的）,flect,flex=bend,表示“弯曲”

flexible/inflexible/reflect/reflection/fragile/rigid/stubborn
记忆：
1. 词根flex表示“折”，flexible [ 5fleksEbl ] 可折叠的， adj. 柔韧性, 易曲的, 灵活的 We should take flexible policy about international relation. 对国际关系，我们应该采取灵活的政策。
2. inflexible [ in5fleksEbl ] adj. 不屈的, 不屈挠的, 顽固的 Nothing will stop the inflexible boy realizing his dream. 什么也阻止不了这个不屈不挠的男孩实现他的梦想。
3. reflect [ ri5flekt] 折回去的， v. 反射, 反映, 细想 The beams were reflected to the bed. 光线被反射到了床上。
4. reflection [ ri5flekFEn ] n. 反射, 映象, 倒影, 反省 The reflection in the water made the tree more attractive. 水中的倒影使树更迷人。
5. fragile [ 5frAdVail ] adj. 易碎的, 脆的 Be careful! The glass bottle is fragile. 小心！玻璃瓶是易碎的。
6. rigid [ 5ridVid ] adj. 刚硬的, 刚性的, 严格的 The rule is rigid but the man is flexible. 规则是刚性的，但人是弹性的。
7. stubborn [ 5stQbEn ] stub-born stub, 树桩；stubborn, 生来就象树桩一样不动摇， adj. 顽固的, 固执的, 坚定的 How did you manage to persuade the stubborn manager to change his idea?你是怎样说明那个固执的经理改变他的主意的？
另类阅读：
Her words reflected her flexible approach. She had no fragile heart and was not stubborn-minded, but inflexible in determination. She could adapt herself to rigid rules.