单选题 Healthy diet and enough exerciese are the key ______ good health. 的答案

成人教育远程网络教育函授网上考试【专科英语I】课程在线考试模拟试题正确答案解析，免费查看【专科英语I】作业答案。
题目内容：
Healthy diet and enough exerciese are the key ______ good health.
题目选项

参考答案价值：100%