四、单项选择请从各题所给选项中选择最佳答案。（共10分, 每小题1分）
（ ）26. This isn’t my pencil-case. ______ is blue.
A. I B. Me C. Mine D. My
（ ）27. Our family will leave for Paris ______ Sunday morning.
A. on B. at C. in D. for
（ ）28. —Where was Gary at 10 yesterday? — He ______ in the library at that time.
A. was reading B. reads C. is reading D. will read
（ ）29. Put on your coat, ____ __ yo u may catch a cold.
A. and B. so C. but D. or
