问题 单项选择题

离心式冷凝水泵是电厂的专用泵,多用于输送冷凝器内聚集的冷凝水,其主要特点是()。

A.有较高的扬程 

B.流量随负荷变化 

C.有较高的气腐蚀性 

D.有较高的耐磨性能

答案

参考答案:C

解析:

离心式冷凝水泵是专供输送水蒸气冷却后的冷凝水用是电厂的专用泵.多用于输送冷凝器内聚集的凝结水。由于冷凝器内部真空度较高,因此要求有较高的气蚀性能。

考点

泵、风机和压缩机

阅读理解

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West High School Bake Sale

Come and support our band and buy some delicious baked goods!

Friday, September 20th, 2:00 – 4:00 p.m.

In the hall by the office after school

Cookies: 25 cents each or 5 for $1

Brownies: 50 cents each or 3 for $1.25

Cake by the slice: $1

Whole cakes: $8

Proceeds go toward sending our band to Nationals.

Ad.2

SHIPPING AND HANDLING CHARGES

Ups or U.S. Parcel Post are the standard methods for continental U.S. shipments.

ORDER TOTAL                             GROUND                   EXPEDITED GROUND

9-12 working days                   4-5 working days

$0.00 to $30.00                                 $4.50                                                     $5.50

$30.01 to $60.00                     $7.25                                                $8.25

$60.01 to $100.00                            $9.50                                                   $10.50

$100.01 to $200.00                          $11.50                                                   $12.50

Add $7.00 to Ground Rates for 3 Days.

小题1:How much money can you save if you buy 3 brownies?

A.25 cents.

B.50 cents.

C.75 cents.

D.1.25 dollars.小题2:Which of the following gives you the most for your money if you buy the baked goods?

A.4 cookies.

B.2 brownies.

C.5 cookies.

D.One slice of cake.小题3:If you wish to receive an order totaling $90.00 within 3 days, how much would the shipping cost?

A.$10.50.

B.$16.50.

C.$15.00.

D.$26.50.小题4:How much should you pay for an order totaling $50 for the expedited ground?

A.$1

B.$7.25

C.$8.25

D.$15.5

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