【单选题】"Cars are not as safe as they used to be. They're more fuel-efficient, more environmentally sound, and better at surviving a 5 m.p.h. collision. But none of that adds up to safety." Does the speaker o...
【简答题】拟在列管式换热器中用初温为 20 °C 的水将流量为 1.25kg / s 的溶液(比热容为 1.9kJ / kg × °C、密度为 850kg / m 3 )由 80 °C 冷却到 30 °C 。换热直径为 f 25 × 2.5mm 。水走管程、溶液走壳程,两流体逆流流动。水侧和溶液侧的对流传热系数分别为 0.85kW / (m 2 × °C ) 和 1.70kW / (m 2 × °C ) ,...
【单选题】Please Listen to the following TED talk and answer the questions followed. (2分17秒-3分08秒) The speaker worked with other scientists to analyze earth climate observations. In 1981,they published an artic...
A.
observed warming of 0.4 degrees Celsius in the prior century was consistent with the greenhouse effect of increasing CO2
B.
That Earth would likely warm in the 1980's, and warming would exceed the noise level of random weather by the end of the century
C.
T he 21st century would see shifting climate zones, creation of drought-prone regions in North America and Asia, erosion of ice sheets, rising sea levels and opening of the fabled Northwest Passage
D.
All of these impacts have since either happened or are now well under way
【简答题】听下面一段材料,回答第1至4题。 1. What's the speaker mainly talking about? [ ] A. His school life. B. His family. C. His brother. 2. How does the speaker like his brother? [ ] A. Naughty. B. Honest. C. Depe...