A、Pull them out by hands. B、Throw the sinking fish away. C、Pour more water into the container. D、Add more salt to the water. D推理

There are different ways to store fish. Two ways to keep fish for future use are canning and freezing. Two other methods are drying and smoking. (32)Today we will introduce how to prepare dried fish. Begin with fish that are just out of the water. If the fish are small, leave their heads on. Cut off the heads if the fish are longer than 20 centimeters or weigh more than 115 grams. Now clean the freshly caught fish, cut off the scales and cut open the stomach to remove everything inside. Then wash the fish in clean water and rub salt into them. Next, put the fish in a container with a solution of 300 grams of salt and one liter of water, (33)which can remove the blood from the meat. After keeping the fish in the saltwater for about 30 minutes, wash them again in clean water. Then, (34) put the fish in a solution that has more salt in the water. The water should be salty enough so that the fish float to the top. Cover the container with a clean piece of wood and place a heavy stone on the wood to hold it down, leaving them there for about six hours. After that, remove the fish from the saltwater and place them on a clean drying table with a clean piece of white cloth covered. (35)For best results, put the drying table under a tree, turning the fish over every other day. Small fish will dry in about three days if the air is dry while large ones will take a week or ten days to dry.
32. What does the passage mainly talk about?
33. Why should people keep the fish in the saltwater?
34. What should people do if the fish sink to the bottom of the container?
35. What can be inferred about drying fish?