一、单项选择
1. They _____in the school, ______ them are working hard.
A. study all, all B. all study, all of C. study all, all of D. all study, all
2. My grandma is used __________ in China.
A. to live B. living C. to living D. to lives
3. He always got full ________ on a test when he was in junior high school.
A. mark B. a mark C. marks D. a marks
