What do you mean by reeling of silk ?

Reeling silk is the process by which a number of cocoon baves are reeled together to produce a single thread.

Explanation:

Silk reeling is the process by which a number of cocoon baves are reeled together to produce a single thread. This is achieved by unwinding filaments collectively from a group of cooked cocoons at one end in a warm water bath and winding the resultant thread onto a fast moving reel.

Hope this helps! :)

i would say "están" :

answer is a: las

explanation:

the reason for this answer is becouse it's a plural frase which talks more then one thing