_____alltherepresentativesstillnotthere，themeetingwaspostponedforseveralhours.
B
with 加名词短语，表示原因，本句意思为： “因为所有的代表还没有到场，会议 被推迟了好几个小时 ”。而 because(因为)引导的是原因状语从句，其后必须是个从句。 by 为“到⋯⋯ 为止 ” 。
Thegirlwhofoundtheringreceivedagenerous_____offivepounds.
_____alltherepresentativesstillnotthere，themeetingwaspostponedforseveralhours.
Bothofmybrothersarenowmarried，soIhavetwo_____.
Childrenwhoareover-protectedbytheirparentsmaybecome_____.
Mywalletisnowheretobefound.I_____itwhenIwasonthebus.