I.单项选择（共12分，每小题1分）
( ) 1. —What are ______ doing? — They’re listening to a CD.
A. they B. them C. their D. theirs
( ) 2. Look! They are having ______ good time playing basketball.
A. a B. the C. an D. /
( ) 3. Lily talks on the phone ______ about three hours every day.
A. on B. in C. for D. at
( ) 4. Bruce ______English right now.
A. study B. studies C. is studying D. are studying
