________time goes by, Mother's hair has
题型：选择题
问题：
________time goes by, Mother's hair has turned grey and the wrinkles on her face deeper.[ ]
A. As
B. With
C. While
D. Because
________time goes by, Mother's hair has turned grey and the wrinkles on her face deeper.[ ]
A. As
B. With
C. While
D. Because