常压下一般气体的流速范围是()。
A.1~3m/s
B.3~5m/s
C.10~20m/s
D.0.5~1m/s
参考答案:C
I don't mind her criticizing me,but ________ is how she does it that I object to.
A.it
B.that
C.this
D.which
能用来鉴别NaOH、NaCl、H2SO4的一种试剂是( )
A.紫色石蕊试液
B.酚酞试液
C.氯化钡溶液
D.碳酸钾溶液