1 swallow and 4 finches = 1 finches and 5 swallows, … ②

Subtract 1 bird 1 swallow from both sides to get 3 birds =4 swallows, 1 swallow =34 birds, … ③

Bring ③ into ① and get:

5 finches +6×34 finches = 9500g,

192 finches = 9500g,

1 sparrow = 9500× 219g =1000g,

Bring in ③ and you get: 1 swallow = 34×1000g = 750g;

A: Each swallow is 750g, and each sparrow1000g.