People should _________ down trees in order to protect the environment.

Have you seen______ pen? I left one here this morning.— Is it___________ black one? I think I saw it somewhere.

My sister doesn’t look ______ my mother, but she speaks ____ my father does

It’s not enough an English club. You should also read English newspapers often.- Thanks for your advice.

It’s going to rain.Tom，will you please help me________the clothes on the line