长椅的板条看起来很光滑。

The ___slats of the bench look smooth.

婴儿床的围栏由细木条制成，以防止孩子掉下来。

The crib's sides are made of wooden ___slats to prevent the baby from falling out.

在起飞阶段，飞行员放下了缝翼以增加升力。

During takeoff, the pilot lowered the ___slats to increase lift.