Ⅰ. 单项选择(每小题2分，共20分)
1. The car accident happened ________ a cold winter morning. Three people were killed in the accident.
A. in B. on
C. at D. of
2. (2015·广东)Could you please give me a hand? I can't complete the task on time ________ your help.
A. without B. under
C. with D. for
