Abeamoflightwillnotbendroundcornersunless________(make)todosowiththehelpofareflectingdevice
________(fail)severaltimes,theyneedsomeencouragement.
Ishallneverforget________(meet)thelatePremierZhouduringhisinspectionofourfactory.
Herefusedtotelluswhetherhe________(undertake)thejob.
Wooddoesnotconductelectricity;________.
Howlong________they________(dig)theditch?