A, R4 access circuit resistance increases, external circuit total resistance increases, total current I decreases, external voltage U increases, voltage of R 1 increases, current expression number I 1 increases, current I2 of R2 decreases, and voltage expression number UV=U-I2(R2+R5) increases. So, A is wrong.

The voltages of B and R3 decrease, and the charging amount of the capacitor decreases. Therefore, B is correct.

The voltage and power of C and R5 increase, so C is correct.

D, the total power of the power supply P = ei.i decreases, and the total power becomes smaller. So, d is wrong.

So choose BC.