____I was walking to school, I saw a boy crying in the street.
This is the first thing you are ________ after you get there.
Yao Ming is a famous basketball star_______ is playing in the NBA . A. which B. who C. when D. where
Whose guitar is this? Susan plays the guitar. It must _______.
_________that river ________very clean?
If I _______ you , I _______ do that .