【单选题】____是科学理论、创新思维的源泉,是检验真理的试金石
【单选题】____ 是科学理论、创新思维的源泉,是检验真理的试金石.( )
【单选题】工程项目目标系统的建立过程是指( )。
A.
投资机会研究—初步可行性研究—可行性研究—项目评估
B.
工程项目构思—识别需求—提出工程项目目标—建立目标系统
C.
工程项目构思—识别需求—可行性研究—项目评估
D.
投资机会研究—初步可行性研究—可行性研究—建立目标系统
【简答题】水体污染是指大量污染物质排入水体,超过水体的____,使水质恶化,水体及其周围的_____遭到破坏,对人体健康、生活以及生产活动等造成威胁和损失的情况。水体污染的来源主要有____、____和____。
【单选题】What is the professor's attitude toward fuel cells?
A.
He thinks that the technology is not very efficient.
B.
He is hopeful about their development in the future.
C.
He is doubtful that fuel cells will replace fossil fuels.
D.
He is discouraged because of the delays in production.
【单选题】According to the last paragraph, which is NOT true of the new fuel cells? 查看材料
A.
The new fuel cells run on sugar that is easy to find.
B.
The new fuel cells are environment-friendly.
C.
The new fuel cells are biologically degradable.
D.
It will take some time before the new fuel cells can be used in popular products.
【简答题】爱护水资源主要应从______和______两方面做起. (1)防止水体污染 ①水体污染是指大______排入水体,超过水体的______使水质恶化的现象. ②污染来源:______污染、______污染、______污染. ③防止水体污染的措施 A)工业上:应用新技术、新工艺减少污染物的产生,同时对污染的水体______. B)农业上:提倡使用农家肥,合理使用______和______. C)生...
【简答题】There are 3 types of cells and batteries: primary cells, secondary cells, (fuel cells / recharging cells).
【单选题】Johnson's paper ______three processes for generating hydrogen in fuel cells.
【简答题】水体污染越来越严重,怎样防止水体污染呢?