Be uncertain of
不肯定..., 不确定...
🧩 词语组成解析
be
[bi]
v. 是;有，存在;做，成为;发生;
aux. 用来表示某人或某物即主语本身，用来表示某人或某物属于某一群体或有某种性质;
of
[əv]
prep. 关于;属于…的;由…制成;
aux. 助动词 [非标准用语、方言] =have [主用于虚拟语气];
🗣️ 情景例句
Claims, if any, must be made within 30 days after the arrival of the goods.
索赔必须在货物抵达目的地后30天内提出。
You cannot judge a tree by its bark.
人不可貌相。
I apologize for being so angry with you.
我为跟你发火向你道歉。