heteachertoldthemsincelight________(travel)fasterthansound,lightning________(appear)togobeforethunder.
Ishallneverforget________(meet)thelatePremierZhouduringhisinspectionofourfactory.
Abeamoflightwillnotbendroundcornersunless________(make)todosowiththehelpofareflectingdevice
Matteristhename________(give)toeverythingwhichhasweightandoccupiesspace.
Iwonderifhecouldgetit________(do)beforetomorrow.
Howlong________they________(dig)theditch?