题干
Anne felt nervous ____ she gave a speech in front of so many students.
A：for the first time
B：at the first time
C：the first time
D：at first
答案(点此获取答案解析）
C
积、等pH的Ba(OH)2、NaOH和NH3·H2O三种碱溶液，滴加等物质的量浓度的盐酸将它们恰好中和，用去酸的体积分别为V1、V2、V3，则三者的大小关系正确的是