---Wasitunderthetree______youwentawaytalkingtoafriend?---Sure.Butwhen

---Was it under the tree ______ you went away talking to a friend?
---Sure. But when I got back there, the bike was gone.A.thatB.whenC.whereD.while

B解析试题分析：考查时间状语从句：做好此题的关键是正确理解上下文的语境。在此句中，it是代词，指代 the bike，句意为：“当你离开去同朋友谈话的时候，你的自行车是在这树下吗?”“当然，但当我回来时，自行车就不见了。”假若 A，为强调句，句子即为 Was it under the tree that you were away talking to a friend? 把强调部分去掉：句子则为 Under the tree while you were talking to a friend，不成立一个句子。选 B。
考点：考查时间状语从句
点评：此题很容易误选 A，认为这是强调句型。关键是要会判断，平时练习时要有这个意识。it is /was+被强调部分+that/who+…判断方法是去掉it is /was that/who句子不缺成分，即为强调句型。这句话却不是。

感谢回答，我学习了