1．[2010·北京西城二模]Ballet is amazing; you go ,you are likely to find yourself going again and again.
A．as B．once C．unless D．while
1B考查状语从句的连接词。此处once应为：一旦。
2. [2010·云南昆明三中第七次月考]She had just finished her homework ______ her mother asked her to practise playing the piano yesterday.
A. when B. while C. after D. since
