You have to wear a helmet and a life jacket for protection, just you fall into the water.
A. for
B. because
C. so that
D. in case
网友回答
A. for
B. because
C. so that
(答案→)D. in case
解析：考察连词，for 因为， because因为 so that 为了，以致于 in case万一
句意为你一定要带一个头盔，穿一件救生衣，只是以防万一你掉到水里。