Which of the following constraint type

1、Which of the listed types steam traps

Which of the listed types steam traps operates on the principle that hot water flashes to steam when its vapor pressure is rapidly reduced?（）ABall floatBThermostaticCBimetallicDImpulse

2、Which of the following types of hydrau

Which of the following types of hydraulic pumps would be used in a steering system?（）ALobeBScrewCRadial pistonDVolute

3、Of which of the following did the auth

Of which of the following did the author provide a guardedly optimistic view?A［A］GDP growth.B［B］The number of layoffs.C［C］Price indexes.D［D］Output of consumer goods.

4、Which type of backup contains only the

Which type of backup contains only the blocks that have changed since the last level 0 incremental backup?（）A a cumulative level 1 backupB a differential level 1 backupC a full backupD a whole backu

5、Which of the following is true of the

Which of the following is true of the OECD report?AIt criticizes government-funded research.BIt introduces an effective means of publication.CIt upsets profit-making journal publishers.DIt benefits scientific research considerably.

6、Which of the listed types of files is

Which of the listed types of files is the best for producing a fine finish on metal?（）AMillBFloatCWardingDSecond cut