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(本小题满分1 3分) 如图①，一条宽为l km的两平行河岸有村庄A和供电站C，村庄B与A、C的直线距离都是2km，BC与河岸垂直，垂足为D．现要修建电缆，从供电站C向村庄A、B供电．修建地下电缆、水下电缆的费用分别是2／km、4／km． (Ⅰ)已知村庄A与B原来铺设有旧电缆仰，需要改造，旧电缆的改造费用是0.5／km．现 决定利用旧电缆修建供电线路，并要求水下电缆长度最短，试求该方案总施工费用的最小值． (Ⅱ)如图②，点E在线段AD上，且铺设电缆的线路为CE、EA、EB．若∠DCE='θ' (0≤θ≤ )，试用θ表示出总施工费用y()的解析式，并求y的最小值．
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【单选题】Why has climate change become a major issue for both business and government?
A.
The body of scientific evidence is inconclusive.
B.
The solutions to the problems are unanimous.
C.
The weather patterns are becoming increasingly uniform.
D.
The change in climate patterns affects the entire planet.
E.
The effects are confined to national boundaries.
【单选题】What can we infer from the text?
A.
Climate change has caused great damage to most countries in the world.
B.
To stop climate change will greatly improve the development of the world.
C.
It is urgent for human beings to take measures to prevent climate change.
D.
Human beings should build man-made highlands to avoid floods.
【单选题】Where do Louisa and Mrs. Traynor have the conversation?
A.
Louisa’s home
B.
A car
C.
On the pavement
【简答题】利用封闭回路法确定极叉时,如果回路中绝缘节的个数为 时,满足极叉。
【单选题】美国心理学家WoodWorth提出的行为表示式“S-O-R”分别指
A.
S-see，O-organize，R-respond
B.
S-sense，O-organize，R-react
C.
S-stimulus，O-organism，R-reaction
D.
S-stimulate，O-organize，R-respond
E.
S-sensory，O-organism，R-response
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【简答题】补全对话。 假期过后，刚刚返校的Louisa遇到了Josie，她们在一起谈论自己假期都做了什么。 Louisa: 1. ______ this vacation? Josie: I went to visit my grandma in Britain. Louisa: 2 _____ there? Josie: I went hiking in the mountains and visite...
【单选题】What does “12 August” mean by Louisa?
A.
the time for anniversary with Patrick
B.
the time for Will's last day
C.
the time for Louisa's wedding
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