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题目内容双击单词支持查询和收藏哦～
Although the use of cameras to study animal behavior was certainly not ____________, cameras were nevertheless not used to study individual frogs in their natural habitat until 2009.
- A.ideal
- B.unprecedented
- C.laborious
- D.impractical
- E.novel
- F.perfect
B,E显示答案
以上解析由 考满分老师提供。
