First, read the English article below.

Place cleaned and sliced mushrooms on the paper towel. They should only be in one layer, with none of the mushrooms overlapping. If they overlap, the mushrooms may fuse together. It is very important that the mushrooms be absolutely dry. If they have even a little bit of water on them, that water could turn to ice and spoil the mushroom. Continue to lay mushrooms down in single layers, and then placing paper towels over those layers, until you have used up all of the mushrooms you want to dry. It should go without saying that you should use a large-ish paper bag that can fit all of the paper towels and mushrooms. The paper bag will allow water vapors to pass through it as the mushrooms dry. Overtime, your mushrooms will begin to dry in the freezer. This is a much slower process than the other two methods listed above, but is effective--particularly if you are not planning on using your mushrooms immediately. 

Now, please write a short abstract for it in Vietnamese. Abstract:
Xếp khăn giấy lên một mặt phẳng. Xếp một lớp khăn giấy khác lên nấm. Cho nấm được xếp xen kẽ với khăn giấy vào túi giấy. Cho túi giấy vào tủ đông.