had expected there to be so many people present at the meeti

是非谓语动词,在这句中had expected为谓语动词.注意expect的用法,它的词组结构是expect sb.to do sth.现在expect后接的结构是there be ,其中be 为动词,因而要用它的不定式的形式,于是构成expect there to be 的结构,译成“期望有----,希望有----”
因为expect 没有expect doing 的结构,所以不可以用had expected there being的形式