问题 问答题 简答题

按GB/T6536石油产品蒸馏测定法要求,蒸馏汽、煤、柴油其冷凝器冷浴的温度各是多少?为何不同?

答案

参考答案:

蒸馏汽油其冷浴的温度应是0~4℃,煤油和柴油应是0~60℃。冷浴温度之所以根据不同油品调整不同温度,主要是因为汽、煤、柴油的馏程范围不同,汽油中含轻质馏份较多,所以冷浴的温度较低。冷浴温度的确定只要能使试样沸腾后的蒸气在冷凝管冷凝为液体,并使其在管内能正常流动即可。

阅读理解

One day Mrs. Wilson went shopping with Tracy and Ben. They went to the supermarket in the new shopping center.” Why do you buy things here?” Tracy wanted to know. “Because they are cheaper here than at the corner store near our home,” Mrs. Wilson said.” Help me check the prices, please.” The Wilsons were not rich and Mrs. Wilson was always careful with her money. She looked carefully after the prices of things. She bought lots of things in the supermarket. When they got home, the children said,“ We don’t think you saved money by going to the supermarket.” “Of course I did,” Mrs. Wilson said. “ Everything was cheaper there.” “We know,” the children said,“ but we came home by taxi because we had too much to carry. The taxi fare was more than the money that you save! ” Mrs. Wilson added everything up. Her children were right.

小题1:The things at the corner store were ______than those in the supermarket.

A.cheaper

B.nicer

C.more expensive

D.saved a little money小题2:Mrs. Wilson ______ in the end.

A.spent more money

B.paid less money

C.lost some money

D.saved a little money小题3:From the passage we know the children were _________.

A.happy

B.clever

C.tired

D.lazy小题4:Mrs. Wilson will _____________.

A.never call a taxi

B.go on buying things in the supermarket

C.buy things near her home

D.not go shopping with her children小题5:The best title for the passage is ____________.

A.Cutting Price

B.Corner Store

C.Supermarket

D.Shopping

判断题