he teacher told them since light ________ (travel) faster than sound,lightning ________ (appear) to go before thunder.

A beam of light will not bend round corners unless ________ (make) to do so with the help of a reflecting device

Those who’d like to visit the exhibition ________ (sign) your names here.

Agreatnumberofsmallpowerstations________(setup)intheircounty sinceliberation.

Hardlyhadhefinishedhisspeech________theaudiencestartedcheering.