Son: Mum, the twice-cooked ____ we eat today is very delicious! Mum: Oh, really? It’s the ____ of ecological pigs. Son: What are ecological pigs? Mum: Ecological pigs are ___ with green fodder and raised with ecological breeding technology. Son: Sounds interesting. What do they eat then? Mum: They mainly eat grass ______ and rice husks. They are kept in large space, behind which there is an even larger room. When the whether is fine, the pigs are driven outside to eat ___ grass and vegetables in the sun. Son: That is to say, these pigs often do some sports. Mum: You are right. That is why they are ______ than ordinary pigs. Generally, they are about 50 kilos after one year’s breeding, while ordinary pigs are over 130 kilos after 3 months’______. The ecological pigs are not fat and are much healthier, so their meat looks elastic with bright color, and tastes more delicious. Son: I guess their price is much higher than that of ordinary pigs. Mum: Of course. But I think it is ______.