【单选题】There isn't enough land to support human being because______.
A.
most of the world's land is unusable
B.
there are more seas than land in the world
C.
the world's land has already been taken up
D.
the world's land is not distributed equally
【简答题】为了探究实验室里制取二氧化碳的理想反应,你首先可先考虑能生成二氧化碳的反应有哪些。请写出五个能生成二氧化碳的化学方程式: ①__________; ②__________;③___________; ④__________;⑤____________。 考虑到_________反应速率太快,难以收集;____________反应生成的二氧化碳不纯;___________反应需要高温条件,比较困难;...
【单选题】________ he returns to his native land.
B.
It is not before long that
C.
It won’t be long before
【简答题】工业机器人组件连接处设有()或(),防止机器人安装错误。
【单选题】男性,45岁,胃溃疡史8年。近1个月来上腹不适、疼痛、反酸、嗳气等症状明显加重,体重下降3kg。经胃镜检查确诊为胃癌,拟行胃大部分切除术。(2)腌制食品中含有的哪种物质与胃癌的发生密切相关()
【单选题】Land belongs to the city there is ______ thing as private ownership of land.
【单选题】生产资料私人所有,以雇佣劳动为基础的私有制经济是( )
【简答题】工业机器人组件连接处设有( )或( ),防止机器人本体安装错误。