A:(NH4)2SO4
B:NH4HCO3
C:NH4NO3
D:NH4C1
—I want to go out for a dinner. Is there a _________ near here? —Yes, there is one across from the post office.
让钢琴和手风琴都发出C调的“do”,我们能区分开是钢琴还是手风琴的声音,这是依据 ( )