在管壳式换热器中安装折流挡板的目的,是为了加大壳程流体的(),使湍动程度加剧,以提高壳程对流传热系数。
A、黏度
B、密度
C、速度
D、高度
参考答案:C
Directions:
Study the pictures carefully and write a composition entitled The Increasing Use of Private Cars in China. Base your essay on the outline given below:
1. show your understanding of the pictures,
2. present possible reasons for the phenomenon, and
3. draw a conclusion.
You should neatly write 160—200 words on ANSWER SHEET 2.
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