筑巢

The nesting instinct is proper to birds.

筑是鸟类的本能。

The swallows are nesting in the woodshed.

燕子小棚里筑呢。

The swallows are building a nest under the roof of our house.

燕子们的屋檐下筑。

Some birds build nests of twigs.

一些鸟用枝筑。

Summer migrants nest here.

夏天候鸟来这里筑。