高等继续教育 / 高级英语I
正确率：100%
题型描述: 单选题
This has never been tried before. So it’s natural that we’ll run _ _ _ _ _ _ _ all kinds of difficulties.
A.by
B.into
C.upon
This has never been tried before. So it’s natural that we’ll run _ _ _ _ _ _ _ all kinds of difficulties.
A.by
B.into
C.upon
参考答案：
佳题速递：