Before replacing a piston you should check the rings to see that all clearances and gaps are within the permissible （）.

[试题]B．eforeyoumailthisletter，youshouldcheckagainwhetheryouhave_______itornot.A.sunkB.sighedC.soughtD.sealed

[问答题]You should look around before you cross the street.

[单选题]You should [convert]RMB into foreign currency before you go abroad.A.alterB

[单选题]You should have [blended]the butter with the sugar thoroughly before you he

[单选题]You should have [blended]the butter with the sugar thoroughly before you he

However, I think there are a number of questions you should ask yourself before

Fuel injection begins during the compression stroke, before the piston reaches _

[单选题]What should be prepared before disassembly of cylinder for main engine or auxiliary engine?

[单选题]You should work for __________ if you become an editor of the magazine.A． just nine hours a dayB. no less than nine hours a day C. about ten hours a dayD. less than 25 hours a week

[单选题]_____you may have, you should gather your courage to face the challenge.A． However a serious problemB． What a serious problemC． However serious a problemD． What serious a problem