已知方程组3x+5y=73x-5y=11①+②得x=______；①-②得y=_

成年人收到持续寒冷刺激时，产热量大为增加的主要方式是（）。

A.肝脏代谢增强

B.基础代谢增强

C.肌紧张产热

D.骨骼肌代谢增强

E.褐色脂肪组织产热

Living in a foreign culture can be exciting, but it can also be confusing. A group of Americans who taught English in other countries recently discussed their experiences. They decided that miscommunications were always possible, even over something as simple as "yes" and "no".

On her first day in Micronesia, an island in the Pacific, Lisa thought people weren’t paying any attention to her. The day was hot. She went into a store and asked, "Do you have cold drinks" The woman there didn’t say anything. Lisa repeated the question. Still the woman said nothing. She later learned that the woman had answered her: She had raised her eyebrows, which in Micronesia means "yes".

Jan remembered an experience she had in Bulgaria, a country in Europe. She went to a restaurant that was known for its cabbage. She asked the waiter, "Do you have cabbage today" He nodded his head. Jan waited, but the cabbage never came. In that country, a nod means no.

Tom had a similar problem when he arrived in India. After explaining something in class, he asked his students if they understood. They answered with many different nods and shakes of the head. He thought some people had not understood, so he explained again. When he asked again, they did the same thing. He soon found out that his students did understand. In India, people nod and shake their heads in different ways depending on where they come from. You have to know where a person is from to understand whether they mean "yes" or "no".

Which of the following is TRUE according to(根据) this passage（）

A．In Bulgaria, nodding heads means "no".

B．Jan taught English on a Pacific island.

C．Lisa was trying to buy some cabbage.

D．In India, only shaking heads means "yes".

输油站调度无权向上级调度询问全线输油运行情况，如输油量、运行方式、上下站间动态和参数等。

背景

西湖中桥是一座15m的钢筋混凝土整体式简支梁桥，桥宽9.5m，重力式桥台。桥位处地质覆盖层为厚2m的强风化泥岩，桥台持力层为中风化泥岩。桥梁顶面距自然地面线的平均高度为8m。在距桥位3km处有一个大型水泥厂，混凝土所需用的砂石级配良好。施工单位采用满堂式钢管支架直接支撑在地面，为防止支架变形，整个钢管支架设置了多道斜撑和横撑。此外，为确保梁体的外观质量，选用了优质钢模，采取多种固定模板的措施。由于浇筑混凝土时正值高温，采用了水灰比大的混凝土，以延缓混凝土的初凝时间。混凝土浇筑完成后，采用多时段直接洒水养护。拆模后发现梁体外观光整，但在梁底和桥面出现了许多不规则的裂缝，梁底有横向裂缝。
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问题

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说明支架施工确定预拱度应考虑哪些因素

关汉卿的历史剧