如图, 在三棱柱 ABC﹣ A 1 B 1 C 1 中, 点 B 1 在底面 ABC 内的射影恰好是点 C, 点D 是 AC 的中点, 且 DA=DB.(1) 如图, 在三棱柱 ABC﹣ A 1 B 1 C 1 中, 点 B 1 在底面 ABC 内的射影恰好是点 C, 点D 是 AC 的中点, 且 DA=DB.(1) 证明: AB⊥CC 1 . 分类:高考 题型:选择题 查看答案
You will feel cold _______ you dont wear a coat. You will feel cold _______ you dont wear a coat. 分类:高考 题型:选择题 查看答案
We will make fewer mistakes _______ we are careful enough. We will make fewer mistakes _______ we are careful enough. 分类:高考 题型:选择题 查看答案
President Xi encourages all Chinese people to plant trees______ our country can President Xi encourages all Chinese people to plant trees______ our country can be greener and more 分类:高考 题型:选择题 查看答案