Unpenetrable
a. 不能穿入的, 难穿入的
🗣️ 情景例句
A generation raised on junk food could turn out mentally vulnerable.
在零食中长大的一代人，注定精神脆弱。
Happy is the man that owes nothing.
无债一身轻。
The steps are rather narrow.
这些台阶相当窄。