7.<古>(cross)(钉死耶稣的)十字架
See alsofamily tree saddletree shoetree
8.at the top of the tree<非正式>(in highest position)(在行业中)位居首位
9.to be barking up the wrong tree<非正式>(follow wrong course of action)走错路线;搞错方向;想法不对路
Scientists in Switzerland realised that most other researchers had been barking up the wrong tree.瑞士的科学家们意识到, 其他研究者大多搞错了研究方向。