问题
Mom was usually busy ______ my younger sister during the night and she ______ have less sleep.[ ]
A: tending; tended
B: tended; tending to
C: tending; tended to
D: tended to; tending to
B: tended; tending to
C: tending; tended to
D: tended to; tending to
正确答案是：
