1. [2010·河北石家庄市二模]It was not until the train was out of sight they stopped waving their hands.
A. when B.before C.since D.that
1D 此题考查强调句型。此题强调时间状语从句not until the train was out of sight。
2．[2010·陕西宝鸡市质检三]Do you know ____ that made it possible for them to continue their project?
A．what it was B．what was it
C．it was what D．it what was
