问题 问答题 简答题

哪些钢种在加热时容易产生过烧缺陷?

答案

参考答案:

随着钢中含碳量的增加,以及某些合金元素的增加,而产生过烧的可能性在增大,高合金钢由于其晶间物质和共晶体容易熔化而特别容易产生过烧缺陷,过烧敏感性最大的是含铬的合金钢,含镍的合金钢以及含铬、镍的合金钢。

单项选择题
填空题


A: Spot Dictation
Direction: In this part of the test, you will hear a passage and read the same passage with blanks in it. Fill in each of the blanks with the words you have heard on the tape. Write your answer in the corresponding space in your ANSWER BOOKLET. Remember you will hear the passage ONLY ONCE.

The Asian (1) has taken its toll on Hong Kong’s tourist industry, (2) of foreign exchange for the area. VOA Hong Kong correspondent reports on the government’s efforts to revitalize (3) of the territory’s economy.
Hong Kong has been searching for ways to boost its (4) tourist industry. Efforts to lift the territory’s ailing sector (5) after the government appointed Mike Rouse as its (6) commissioner for tourism. Mr. Rouse says in order to (7) tourism, the government plans to strengthen its (8) and to enhance the territory’s image as Asia’s most popular (9) .
Hong Kong is still (10) and great center for tourism, and will always be.
However, in the last two years, tourism has taken (11) . Last year arrivals were down 23% from 1997 with (12) visitors coming here. The decline (13) reduced travel in the region because of the Asian economic crisis. Mr. Rouse says (14) to lift the tourist industry includes promoting entertainment activities in the territory (15) arts and culture events. But what has made tourism officials most excited are the efforts to (16) the Walt Disney Company to build a Disneyland theme park in Hong Kong. Such a project could attract (17) two million visitors a year and create tens of thousands of jobs. While negotiation continue, several Chinese language newspapers (18) that Wait Disney has chosen Shanghai instead of Hong Kong. Mr. Rouse, who has been leading the team (19) the Disneyland theme park here, says the territory is still very much (20) . Disney official say they will decide by the end of next month on where they will locate their second theme park in Asia.