— Is Lily good at singing?　　　—Yes , she is．We often hear her_______ in the next room．

It’s a difficult time, but we will never _____ hope.

Bill’s mother ________ much time in cooking every day.She can cook delicious food.

——Who is knocking at the door?——It ______ Mr. Black, because he_______Washington.

Our government is taking action to improve the environment.