单选题
In the Chinese household, grandparents and other relatives play ______ roles in raising children.
【正确答案】
B
【答案解析】indispensable①必不可少的，必需的[(+to/for)]，如：A library is indispensable to a college. ②不能撇开的，责无旁贷的，如：Taking care of my parents is my indispensable duty. incapable没有能力的；insensible昏迷的，麻木的，冷漠的；infinite无限的；无边的，如：The universe is infinite.