--- Bob,are you free at the moment?I have to ask you some questions. --- _______.
1 think we'd better keep to the subject, ______we'll waste our time.
No one can exactly tell us what .
---Look at the glasses on the desk.Are they David’s?---They belong to him.I saw him go out with glasses just now.
of our classmates are good at basketball.
--- skirt is blue. is red.Which of them do you prefer?--- is OK.I like their styles.