问题
选择题
9. 一I must apologize_____ you know ahead of time．
一That’s all right．
A．for letting not
B．for not letting
C．to let not
D．not to let
答案
答案：B
不定式或动名词的否定式均须在其前面加not，never，可先排除A、C两项。动词apologize后要接for短语，常用：apologize to sb．for doing／having done sth．，不能接动词不定式。故选B.