_______ there are many different types of food, some animals spend their lives eating only one type....
2022-11-20 09:31:19 41次 2015届安徽省高二下学期期中考试英语试卷（解析版） 单项填空 反馈错误 加入收藏 正确率 : 100%
题目内容：
_______ there are many different types of food, some animals spend their lives eating only one type.
A. Since B. Unless C. Once D. While
本题链接：
