適用於選單、按鈕和說明。你的學習內容會保持為英文。
/ˈɒp.ʃə.nəl/
not required; left to choice.
“The extra toppings on the pizza are optional.”
To accept or act in accordance with.
On or in a vehicle or vessel.
Not present in a place or situation.
To take in or soak up something.
a feature that emphasizes something
state of being okay with something or someone