根管预备时错误的做法是

A．需确定根管的工作长度
B．选择好第一支根管锉
C．每支器械扩挫后需彻底冲洗
D．不必按器械型号顺序进行，可跳号
E．至少较第一支锉扩大3号以上

What’s not true about Trust-mart().

A. It’s a Taiwanese supermarket chain.

B. The world largest retailer has agreed to buy Trust-Mart.

C. Wal-Mart will buy Trust-Mart for 1 billion yuan.

D. Buying Trust-Mart will make Wal-Mart the biggest food and department store network in China.