The sad boy sat on the ground, shouting she was crying.
A:when
B:while
C:as
D:as soon as
— What is 16 ____ 4?
— It's 4. 2 ____ 2 is also 4.
隋朝的开国皇帝是李渊。
错误:____ 改正:____
通过置换反应可判断金属活动性顺序,某同学通过实验来比较铜、铝、汞的金属活动性顺序,现有铜、铝、汞的三种单质,如果另外只用一种试剂达到实验目的,则应选用下列试剂中的( )