如图，电源的电动势为E，内电阻为r，三个电阻的阻值均为2r。现闭合开关S，则电阻A消耗的电功率为（  ）

A mgsinθ B ftmgcosθ C mg(sinθ-μcosθ) D mg(sinθ+μcosθ)

A 内能增加，压强增大 B 内能增加，压强减小 C 内能减少，压强增大 D 内能减少，压强减小

A 频率变小，波长变长 B 频率不变，波长变长 C 频率不变，波长变短 D 频率变小，波长变短

A <img width="19" height="19" src="https://www.beizhujiaoyu.com/uploads/202208/20210727163358_6028.jpg" />的读数变大，<img width="18" height="19" src="https://www.beizhujiaoyu.com/uploads/202208/20210727163357_4465.jpg" />的读数变大 B <img width="19" height="19" src="https://www.beizhujiaoyu.com/uploads/202208/20210727163400_6965.jpg" />的读数变大，<img width="18" height="19" src="https://www.beizhujiaoyu.com/uploads/202208/20210727163357_4465.jpg" />的读数变小 C <img width="19" height="19" src="https://www.beizhujiaoyu.com/uploads/202208/20210727163358_6028.jpg" />的读数不变，<img width="18" height="19" src="https://www.beizhujiaoyu.com/uploads/202208/20210727163401_6340.jpg" />的读数变大 D <img width="19" height="19" src="https://www.beizhujiaoyu.com/uploads/202208/20210727163358_6028.jpg" />的读数不变，<img width="18" height="19" src="https://www.beizhujiaoyu.com/uploads/202208/20210727163357_4465.jpg" />的读数变小

A <img width="51" height="32" src="https://www.beizhujiaoyu.com/uploads/202208/20210727163402_7902.jpg" /> B <img width="118" height="31" src="https://www.beizhujiaoyu.com/uploads/202208/20210727163403_7122.jpg" /> C <img width="80" height="31" src="https://www.beizhujiaoyu.com/uploads/202208/20210727163404_8683.jpg" /> D W_f=Fs

A E_O>E_P，U_O>U_P B E_O<E_P，U_O>U_P C E_O>E_P，U_O<U_P D E_O<E_P，U_O<U_P

A H₂ B SiO₂ C MgSO₄ D MgO

A SO₂ B He C NH₃ D HCl

A Cu B Zn(OH)₂ C Cu²⁺ D Zn

A 1．2mol／(L·min) B 6．0mol／(L·min) C 0．6mol／(L·min) D 0．4mol／(L·min)