2. Choose flowers in crowded fixed seafood stalls. Generally, flowers are fresh and affordable. Try not to buy from mobile vendors.
3. You should first choose a large and complete shell and close it tightly, because in the case of hard turning, if the flower shell is not opened but closed tightly, it needs a certain amount of force to open it, and it must be alive.
In the process of selection, you can weigh them one by one. Generally, the weight of each flower is similar. If it is lighter than usual, it must be an empty shell. If you are not sure, you can have a look. Even if it is closed, the empty shell can be easily opened.
5. You can also float the flower nail in the water, sieve it with a basket a few times and then float in the water. If there is an empty shell or mud shell, it will bubble up.