Fill the gaps with age, era, period, spell, or time. 1. the minister said that before the new law came into force there would be a of six months when people could hand in firearms without being prosecuted. 2. the twentieth century will be seen by historians as the of the car. 3. these factories mark the beginning of a new of industrial development for the country.4. for a i thought i would never find a job, but then i was lucky. 5. we had a very cold in february. all the water pipes froze up.