1. Generally speaking, it is best to steam river crabs, so as to maintain the deliciousness of river crabs to the maximum extent. Although it is okay to boil it in water, the umami substances and soluble nutrients in the crab will enter the water, causing the umami flavor to be lost and the nutrition to be greatly reduced.

2. The scientific method should be to place the whole crab belly-side up in a steamer and steam it until cooked. Steaming has a higher temperature than boiling, cooks faster, can shorten cooking time, and can kill microorganisms and parasites in crabs. At the same time, it can also reduce the chance of contamination of the muscles by the gastrointestinal tract in the crab, ensuring that the meat is clean and delicious.