如图所示,电源电压保持不变,R2=4R1,当开关接a点时,电压表的示数为U0,当开关接b点时,电压表的示数( )
A:小于0.25U0
B:大于0.25U0而小于U0
C:等于0.25U0
D:等于U0
如图是几种不同类型的植物,请分析回答:
根据音标,中文意思或首字母,填写单词或词组。
①____Na2S2O3+____HCl→____NaCl+____S+____ SO2↑+____ H2O
②____Zn+____H++____NO3﹣→____Zn2++____NH4++____H2O.
⑴____There's the bus stop.
⑵____Red is stop.
⑶____Green is go.
⑷____The Happy Zoo is there.
⑸____Yellow is wait.
A. B. C.
D. E.