Open the brackets using the verbs in the passive voice:

Do you know soap (to make)? It (to make) of coconut oil, palm oil and tallow, a by-product of the frozen and canned meat. Sometimes oil ftom cotton seeds and soya beans (to use). The oils ( to mix) together in the right proportion according to the type of soap to be made. Caustic acids (to add) to separate the fat from glycerine in the oil. The mixture (to pump) into a large tank which passes stem pipes with holes in them. The steam pours out of the holes into the soap mixture. Salt (to put) to the mixture to remove the glycerine. Then the pumping of steam stops in the whole mixture (to leave) to cool and settle while the glycerine in the salte water (to draw) throught the tap at the bottom of the tank.