skim|skimmed|skimming

煮汤时要撇去浮沫。

___Skim off the foam while making soup.

小石子在水面上轻轻掠过。

The pebble ___skimmed lightly over the water.

燕子轻轻掠过湖面觅食。

The swallow was ___skimming the lake to hunt for food.