精馏塔的进料为过冷液体时,进料线的斜率q/q-1为()。
参考答案:1--∞
下图所示区域在北半球,弧线M为纬线,弧线N为晨昏线,阴影为黑夜;甲乙两地所在经线的经度为120°E;甲地此日正午太阳高度为40°。读图回答下列各题。
小题1:此时太阳直射点的坐标是
A.(120°E,20°N)
B.(60°W,20°N)
C.(120°E,23.5°N)
D.(60°W,23.5°N)小题2:若图中乙点此时的太阳高度是5°,则乙点的地理纬度和正午太阳高度分别为
A.76.5°N,30°
B.80°N,30°
C.76.5°N,10°
D.75°N,35°
He checked out his composition again and again to make sure that no important points had been_______.[ ]
A.found out
B.run out
C.made out
D.left out