_I must apologize for__ahead of time._that is all right.A letting not you know B not letting you know C letting you know not D letting not you know是个对话

问题描述:

_I must apologize for__ahead of time._that is all right.
A letting not you know B not letting you know C letting you know not D letting not you know
是个对话

B not letting you know
for介词 介词后面用动名词
not在动名词前表示否定