【简答题】List the challenges he has run into over all the years he has been chasing his dreams
【单选题】Human and the Environment One of the most pressing challenges that the United States and indeed the world will face in the next few decades is how to alleviate (减轻点)the growing stress that human activ...
A.
It has been estimated that the world's water use could triple in the next two decades.
B.
Plant and animal species are becoming extinct at a greater rate now than at any time in earth's history.
C.
The overuse of antibiotics (抗生素) both in humans and in farm animals has contributed to the growth of antibiotic resistant micro-organisms (微生物).
D.
Yet, there is reason to have hope for the future.
E.
Until recently, very little information was documented about changes and consequences of land usage.
F.
Such changes cause changes in local and regional climate, and will determine the future of agriculture. (46)
【多选题】下列说法正确的是_______________。
A.
图 G 的一棵最小代价生成树的代价未必小于图 G 的其他任何一棵生成树的代价
B.
一个图的最小生成树可能不唯一,但权值最小的所有边一定会出现在解中
C.
若连通图上各边的权值均不相同,则该图的最小生成树是唯一的
D.
一个带权的无向连通图的最小生成树的权值之和是唯一的
【简答题】Please list the challenges you might meet as doctors in the future, not limit to my lecture
【判断题】在Word 2010的开始状态,打开了一个文档,进行“保存”操作后,该文档被保存在新建文件夹下。
【简答题】若连通网络上各边的权值均不相同,则该图的最小生成树有()棵。
【判断题】若连通图上各边的权值均不相同,则该图的最小生成树是唯一的。( )【同济大学2004】