GB／475-1996规定，煤的采样精密度随煤品种不同而有不同的规定，对原煤来说，还与其灰分含量有关。
参考答案：对
光线在两种介质面上的传播遵守反射定律和（）。
A、直射定律
B、折射定律
C、入射定律
D、曲射定律
By the time he had made the journey from Britain to Australia with the submarine, he had become a minor celebrity.
