【简答题】What is the pH of a 0.025mol·L -1 solution of ammonium acetate at 25℃? of acetic acid at 25℃ is 4.74, of the ammonium ion at 25℃ is 9.25, is 14.00.
【单选题】The isoelectric point of an amino acid is defined as the pH at
A.
which the net charges of amino acid equals to the zero
B.
of maximum electrolytic mobility
C.
which the carboxyl group is uncharged
D.
where the amino group is uncharged
【单选题】在PowerPoint2003中,默认情况下,放映全部幻灯片的快捷键是( )。
【单选题】在Excel2010工作表的单元格中可输入()
【简答题】The pH of acid rain is than .
【简答题】(本小题満分14分) 二次函数f(x+1)-f(x)=2x,且f(0)=1 (1)求f(x)的解析式; (2)在区间[-1,1]上,y= f(x)的图像恒在y=2x+m的图像上方,试确定实数m的取值范围。
【简答题】图1-3表明,在默认情况下该数据包请求的服务为(8)。
【单选题】在中文Excel2010工作表中,单元格C4中有公式“=A3+$C$5”,在第2行之前插入一行后,单元格C5中的内容是