你想把妈妈介绍给你的朋友,你可以说:A.This is my mum.B.She is my mum.
—Can you sing a song in English? —No, I __________.
He has two basketballs. One is new, __________ is old.
Bruce, look at your dirty shoes. You’d better __________ them right now.
I met Jack on way home yesterday.
It’s hot __________ summer in Beijing.