Ubah Dari active sentences ke passive sentences

b. then they are transferred to the tank furnace.
c. there they are heated to a temperature of about 100 degree celcius and when the glass is liquid, the temperature is reduced to about 900 degree celcius.
d. arsenic and manganese dioxide are added.
e. discoloration is removed by this.
f. then the liquid is moulded in the required shape.
g. it is cooled slowly.
h. it is stopped cracking by this.
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"The world isn't perfect. But it's here for us, doing the best it can. And that's what makes it so damn beautiful." ~Roy Mustang