如图所示，三只相同的杯子中分别装有质量相等的水、煤油和盐水（ρ_盐水>ρ_水>ρ_煤油），则下列判断正确的是

A．甲杯是煤油，乙杯是盐水，丙杯是水

B．甲杯是水，乙杯是煤油，丙杯是盐水

C．甲杯是盐水，乙杯是水，丙杯是煤油

D．甲杯是煤油，乙杯是水，丙杯是盐水

In relation to the Vietnamese legal system, explain how the courts and other bodies deal with a situation in which there is an absence of a written law to resolve a case. (10 marks)