When H7N9 bird flu first appeared, people didn't know_______ doctors could cure it. A. if B. that C....
2023-01-20 01:26:50 194次 2014-2015学年江苏泰州中学附属初级中学九年级上第一次月考英语试卷（解析版） 单项填空 反馈错误 加入收藏 正确率 : 100%
题目内容：
When H7N9 bird flu first appeared, people didn't know_______ doctors could cure it.
A. if B. that C. what D. why
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