for there to be还是for there being

介词后是用动名词还是不定式？英语习惯是用for there to be还是for there being?请看下面的一道考题：

Considering the dangerous situation, they asked for _________ another meeting.

A. there be                  B. there to be                C. there being                D. there was

【分析】此题很容易误选C，因为空白前有介词 for，所以其后的 there be 的非谓语形式应用 there being，而不用 there to be。其实错了，正确答案应是B。在通常情况下，there be 结构出现在介词后时，要用 there being 的形式，但这有一个例外，就是在介词 for之后只能用there to be。比较(www.nmet168.com)：

They planned on there being another meeting. 他们打算再开一次会议。

They planned for there to be another meeting. 他们打算再开一次会议。

再比较：

They asked about there being another meeting. 他们询问是否要再开一次会。

It's essential for there to be another meeting. 有必要再开一次会。

请再看一题（答案选B)：

For there _________ successful communication, there must be attentiveness and involvement in the discussion itself by all present.(www.nmet168.com)

A. is                        B. to be                        C. will be                        D. being