问题 单项选择题

外形尺寸小巧,重量轻,主要用于仪表调节,不适用于黏度大和含有固体悬浮物颗粒介质的阀门为( )。

A.旋塞阀
B.节流阀
C.安全阀
D.止回阀

答案

参考答案:B

解析: 节流阀是通过改变节流截面或节流长度以控制流体流量的阀门。将节流阀和单向阀并联则可组合成单向节流阀。节流阀和单向节流阀是简易的流量控制阀,在定量泵液压系统中,节流阀和溢流阀配合,可组成3种节流调速系统,即进油路节流调速系统、回油路节流调速系统和旁路节流调速系统。

阅读理解

A group of 1,309 passengers boarded the MS Balmoral on Sunday, in Southampton, England, on a voyage to retrace (重走) the path of the Titanic. The Titanic was the biggest ship in the world when it sailed on its ill-fated first voyage on April 10, 1912. Of the 2,227 passengers and crew aboard, more than l,500 died. The ship, which was headed for New York City, carried the rich and famous on its first voyage. It also carried immigrants who were seeking a better life in America.

Relatives of people who sailed on the Titanic, historians, authors and people fascinated by the story of the unsinkable ship were on the Balmoral. They wanted to remember the Titanic and those who died on her first and last voyage.

The Balmoral was following Titanic’s original route from Southampton. First, the modern-day cruise liner docked (进港) in the port of Cherbourg, France, where the Titanic had picked up more passengers. On Monday afternoon, the Balmoral stopped in Cobh, Ireland, the Titanic’s last port of call before sailing to New York.

The Balmoral then sailed the North Atlantic Ocean to the location where the Titanic hit an iceberg. On Sunday, April 15, at 2:20 a.m. — the time the Titanic went down - passengers and crew held a memorial service. The next two days were spent in Halifax, Canada, where many victims of the Titanic are buried. Then, the Balmoral reached its final destination in New York City, where the Titanic was supposed to dock — but never did.

So far, several teams of divers have explored the site. They have recovered items such as dishes and silverware and put them on public display. And the Titanic and its passengers and crew have been remembered in books, movies and TV programs. But there’s a much more important contribution that the Titanic has given us. After she sank, lawmakers and ship builders made ships safer. It took a terrible tragedy to make ship travel safer for all.

小题1:We learn from the first paragraph that _____.

A.the Titanic sank on its second voyage

B.about 700 passengers of the Titanic survived

C.less than 2,000 passengers boarded the Titanic

D.all the passengers’ hopes of the Titanic lay in America小题2:Which of the following shows the correct route of the Balmoral?

a. Halifax  b. New York City   c. Cobh   d. Southampton e. Cherbourg

A.d-e-c-a-b

B.e-d-a-b-c

C.e-c-a-b-d

D.d-c-e-a-b小题3:What might be the most important contribution of the Titanic?

A.Its site attracts many exploration teams.

B.It has made later ships more secure.

C.Some of its items are on public display.

D.More trips are planned to its site.小题4:What would be the best title for the text?

A.The unsinkable ship

B.The Titanic today

C.The Titanic’s route

D.Sailing through history

多项选择题