Haze (雾霾)appears around us. Let’s do ________ helpful to protect the environment.
He sings ________ and he is a ________ singer(歌手).
—Can you sing the English song? —Yes.I ________.
Yao Ming can play ________ basketball,but he can’t play ____ violin.
—________ —He wants to join the swimming club.
My sister can’t ________ in a river.