A：容量瓶中原有少量的蒸馏水
B：移液时，不慎将液体流到瓶外
C：容量瓶盛过KOH溶液，使用前未洗涤
D：定容时俯视刻度线和液面
选词填空
A．eighteen． B．nineteen C．sixteen D．fourteen E．seventeen
—How was your recent trip to Sichuan? —I've never had_______ one before.
