— I must apologize for ahead of time.
— That’s all right.
A. letting you not know
B. not letting you know
C. letting you know not
D. letting not you know
网友回答
A. letting you not know
(答案→)B. not letting you know
C. letting you know not
D. letting not you know
解析：考查动名词否定形式。Apologize for sth因为sth道歉；for是介词，后面接动名词，动名词的否定形式在前面直接加Not。句意：我必须因为没有提前让你知道向你道歉。故B正确。