The density of water is per cubic centimeter 1g, that is, the volume of 1g water is 1cm, so the volume of 200g water is 200cm. And 200 cubic centimeters =200 milliliters = 200 grams, so 200 milliliters of water is equal to 4 Liang.

1g = 0.002kg, 1g = 1000mg (mg), 1g = 0.00 1kg (kg), 1g = 0.02Liang.

About the introduction of two.

The second is the traditional high-quality unit in East Asia. China appeared before the Han Dynasty, and then spread to Japan, Korean Peninsula, Vietnam and other places. The actual quality is worse from generation to generation, and it has also changed since it was spread to various places. The traditional 1 kg is equal to 16, so there is an idiom that is half a catty. 1 equals 3 1.25g, which is different from 1 currently used in China.

The amount used in medicine in Han Dynasty is different from that commonly used in Han Dynasty. Han inherited the Qin system, and the medical beam continued to use the Qin system. Therefore, two of Zhang Zhongjing's medical works in Han Dynasty are Qin Liang, which is equivalent to 3 grams. At the end of Sui Dynasty, one kilogram was equivalent to 222.73 grams, and one or two kilograms was equivalent to 13.92 grams.