题干
Some people waste too much water. They don't believe that it can _______ some day.
A：keep out
B：run out
C：be run out
D：run out of
答案(点此获取答案解析）
B
Some people waste too much water. They don't believe that it can _______ some day.
A：keep out
B：run out
C：be run out
D：run out of
,1 mol醋酸酐与1 mol水反应，可得2 mol醋酸。某饱和一元醇A 7g跟醋酸酐反应，生成醋酸某酯7.9g，反应后回收到1.2g A，则A的相对分子质量为( )
